[llvm-shlib] Fix the i686 MSVC triple check for listing symbols to ex…

…port in LLVM-C.dll

https://reviews.llvm.org/D47381 / eb46c95
changed the triples set up by GetHostTriple.cmake for i686 MSVC
from i686-pc-win32 to i686-pc-windows-msvc without changing
the corresponding condition in llvm-shlib.

Since then, the 32 bit x86 build of LLVM-C.dll has contained no
exported symbols at all.

Differential Revision: https://reviews.llvm.org/D109493

llvm/tools/llvm-shlib/CMakeLists.txt

@@ -124,7 +124,7 @@ if(LLVM_BUILD_LLVM_C_DYLIB AND MSVC)
   list(REMOVE_DUPLICATES LIB_NAMES)
 
   # The python script needs to know whether symbols are prefixed with underscores or not.
-  if(LLVM_HOST_TRIPLE STREQUAL "i686-pc-win32")
+  if(LLVM_HOST_TRIPLE MATCHES "i?86-.*win.*")
     set(GEN_UNDERSCORE "--underscore")
   else()
     set(GEN_UNDERSCORE "")