CMake: cxxabi.h is only available to C++ compilers, use the right che…

…ck macro.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181019 91177308-0d34-0410-b5e6-96231b3b80d8

cmake/config-ix.cmake

@@ -4,6 +4,7 @@ if( WIN32 AND NOT CYGWIN )
 endif()
 
 include(CheckIncludeFile)
+include(CheckIncludeFileCXX)
 include(CheckLibraryExists)
 include(CheckSymbolExists)
 include(CheckFunctionExists)
@@ -37,7 +38,7 @@ endfunction()
 check_include_file(argz.h HAVE_ARGZ_H)
 check_include_file(assert.h HAVE_ASSERT_H)
 check_include_file(ctype.h HAVE_CTYPE_H)
-check_include_file(cxxabi.h HAVE_CXXABI_H)
+check_include_file_cxx(cxxabi.h HAVE_CXXABI_H)
 check_include_file(dirent.h HAVE_DIRENT_H)
 check_include_file(dl.h HAVE_DL_H)
 check_include_file(dld.h HAVE_DLD_H)