[flang][rt] Add install target for header files

[clementval]

Header files of the runtime were not installed. This patch adds an install target to install the headers under the include directory similar to the flang header files.

[vzakhari]

Thank you, Valentin!

[wangzpgi]

Thank you Valentin!

[llvm-ci]

LLVM Buildbot has detected a new failure on builder clang-aarch64-sve-vla running on linaro-g3-01 while building flang-rt at step 7 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/17/builds/12250

Here is the relevant piece of the build log for the reference

Step 7 (ninja check 1) failure: stage 1 checked (failure)
******************** TEST 'SanitizerCommon-msan-aarch64-Linux :: compress_stack_depot.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/./bin/clang  --driver-mode=g++ -gline-tables-only -fsanitize=memory   -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta  -funwind-tables  -I/home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test -ldl /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp -fsanitize-memory-track-origins=1 -o /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp # RUN: at line 1
+ /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/./bin/clang --driver-mode=g++ -gline-tables-only -fsanitize=memory -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta -funwind-tables -I/home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test -ldl /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp -fsanitize-memory-track-origins=1 -o /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp
env MSAN_OPTIONS="compress_stack_depot=0:malloc_context_size=128:verbosity=1"  /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp 2>&1 | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp --implicit-check-not="StackDepot released" # RUN: at line 2
+ env MSAN_OPTIONS=compress_stack_depot=0:malloc_context_size=128:verbosity=1 /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp '--implicit-check-not=StackDepot released'
env MSAN_OPTIONS="compress_stack_depot=-1:malloc_context_size=128:verbosity=1"  /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp 2>&1 | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp --check-prefixes=COMPRESS # RUN: at line 3
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp --check-prefixes=COMPRESS
+ env MSAN_OPTIONS=compress_stack_depot=-1:malloc_context_size=128:verbosity=1 /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp
env MSAN_OPTIONS="compress_stack_depot=-2:malloc_context_size=128:verbosity=1"  /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp 2>&1 | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp --check-prefixes=COMPRESS # RUN: at line 4
+ env MSAN_OPTIONS=compress_stack_depot=-2:malloc_context_size=128:verbosity=1 /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp --check-prefixes=COMPRESS
env MSAN_OPTIONS="compress_stack_depot=1:malloc_context_size=128:verbosity=1"  /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp 2>&1 | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp --check-prefixes=COMPRESS,THREAD # RUN: at line 5
+ env MSAN_OPTIONS=compress_stack_depot=1:malloc_context_size=128:verbosity=1 /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp --check-prefixes=COMPRESS,THREAD
env MSAN_OPTIONS="compress_stack_depot=2:malloc_context_size=128:verbosity=1"  /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp 2>&1 | FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp --check-prefixes=COMPRESS,THREAD # RUN: at line 6
+ env MSAN_OPTIONS=compress_stack_depot=2:malloc_context_size=128:verbosity=1 /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/stage1/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/msan-aarch64-Linux/Output/compress_stack_depot.cpp.tmp
+ FileCheck /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp --check-prefixes=COMPRESS,THREAD
/home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp:53:14: error: COMPRESS: expected string not found in input
// COMPRESS: StackDepot released {{[0-9]+}}
             ^
<stdin>:89:55: note: scanning from here
MemorySanitizer: StackDepot compression thread started
                                                      ^
<stdin>:90:18: note: possible intended match here
MemorySanitizer: StackDepot compression thread stopped
                 ^

Input file: <stdin>
Check file: /home/tcwg-buildbot/worker/clang-aarch64-sve-vla/llvm/compiler-rt/test/sanitizer_common/TestCases/compress_stack_depot.cpp

-dump-input=help explains the following input dump.

Input was:
<<<<<<
            .
            .
            .
           84: invalid: c00000000000 - cfffffffffff 
           85: origin-10-13: d00000000000 - dfffffffffff 
           86: allocator: e00000000000 - e3ffffffffff 
           87: app-15: e40000000000 - ffffffffffff 
           88: MemorySanitizer init done 
           89: MemorySanitizer: StackDepot compression thread started 
check:53'0                                                           X error: no match found
           90: MemorySanitizer: StackDepot compression thread stopped 
...