Forward the LLVM_ENABLE_LIBCXX CMake parameter to the mlir standalo…

…ne test

This allows to build and test MLIR with `-DLLVM_ENABLE_LIBCXX=ON`.

mlir/examples/standalone/test/lit.site.cfg.py.in

@@ -23,6 +23,7 @@ config.llvm_bindings = "@LLVM_BINDINGS@".split(' ')
 config.host_os = "@HOST_OS@"
 config.host_cc = "@HOST_CC@"
 config.host_cxx = "@HOST_CXX@"
+config.enable_libcxx = "@LLVM_ENABLE_LIBCXX@"
 # Note: ldflags can contain double-quoted paths, so must use single quotes here.
 config.host_ldflags = '@HOST_LDFLAGS@'
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"

mlir/test/Examples/standalone/lit.local.cfg

@@ -1,3 +1,4 @@
 config.substitutions.append(("%cmake", config.host_cmake))
 config.substitutions.append(("%host_cxx", config.host_cxx))
 config.substitutions.append(("%host_cc", config.host_cc))
+config.substitutions.append(("%enable_libcxx", config.enable_libcxx))

mlir/test/Examples/standalone/test.toy

@@ -1,4 +1,4 @@
-# RUN: %cmake %mlir_src_root/examples/standalone -DCMAKE_CXX_COMPILER=%host_cxx -DCMAKE_C_COMPILER=%host_cc -DMLIR_DIR=%llvm_lib_dir/cmake/mlir ; %cmake --build . --target check-standalone | tee %t | FileCheck %s
+# RUN: %cmake %mlir_src_root/examples/standalone -DCMAKE_CXX_COMPILER=%host_cxx -DCMAKE_C_COMPILER=%host_cc -DLLVM_ENABLE_LIBCXX=%enable_libcxx -DMLIR_DIR=%llvm_lib_dir/cmake/mlir ; %cmake --build . --target check-standalone | tee %t | FileCheck %s
 
 # CHECK: Passed: 3
 # UNSUPPORTED: windows, android

mlir/test/lit.site.cfg.py.in

@@ -23,6 +23,7 @@ config.llvm_bindings = "@LLVM_BINDINGS@".split(' ')
 config.host_os = "@HOST_OS@"
 config.host_cc = "@HOST_CC@"
 config.host_cxx = "@HOST_CXX@"
+config.enable_libcxx = "@LLVM_ENABLE_LIBCXX@"
 config.host_cmake = "@CMAKE_COMMAND@"
 # Note: ldflags can contain double-quoted paths, so must use single quotes here.
 config.host_ldflags = '@HOST_LDFLAGS@'