Revert "[runtimes] Probe for -nostdlib++ and -nostdinc++ with the C compiler" (#113653)

Reverts llvm/llvm-project#108357

Breaks https://lab.llvm.org/buildbot/#/builders/164/builds/3908 and
similar bots

NOKEYCHECK=True
GitOrigin-RevId: 240e4780680f0d6a760be1b9ea432f410424b3a5

Author: vitalybuka

cmake/config-ix.cmake

@@ -34,13 +34,9 @@ endif()
 # required during compilation (which has the -nostdlib++ or -nodefaultlibs). libc is
 # required for the link to go through. We remove sanitizers from the
 # configuration checks to avoid spurious link errors.
-#
-# Adding flags to CMAKE_REQUIRED_FLAGS will include the flags both when testing
-# compilation of C and C++. Therefore test to make sure that the flags are
-# supported by the C compiler driver, before deciding to include them.
 
-llvm_check_compiler_linker_flag(C "-nostdlib++" C_SUPPORTS_NOSTDLIBXX_FLAG)
-if (C_SUPPORTS_NOSTDLIBXX_FLAG)
+llvm_check_compiler_linker_flag(CXX "-nostdlib++" CXX_SUPPORTS_NOSTDLIBXX_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
 else()
   llvm_check_compiler_linker_flag(C "-nodefaultlibs" C_SUPPORTS_NODEFAULTLIBS_FLAG)
@@ -51,7 +47,7 @@ endif()
 
 # Only link against compiler-rt manually if we use -nodefaultlibs, since
 # otherwise the compiler will do the right thing on its own.
-if (NOT C_SUPPORTS_NOSTDLIBXX_FLAG AND C_SUPPORTS_NODEFAULTLIBS_FLAG)
+if (NOT CXX_SUPPORTS_NOSTDLIBXX_FLAG AND C_SUPPORTS_NODEFAULTLIBS_FLAG)
   if (LIBUNWIND_HAS_C_LIB)
     list(APPEND CMAKE_REQUIRED_LIBRARIES c)
   endif ()
@@ -86,7 +82,7 @@ if (NOT C_SUPPORTS_NOSTDLIBXX_FLAG AND C_SUPPORTS_NODEFAULTLIBS_FLAG)
   endif()
 endif()
 
-if (C_SUPPORTS_NOSTDLIBXX_FLAG OR C_SUPPORTS_NODEFAULTLIBS_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG OR C_SUPPORTS_NODEFAULTLIBS_FLAG)
   if (CMAKE_C_FLAGS MATCHES -fsanitize OR CMAKE_CXX_FLAGS MATCHES -fsanitize)
     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fno-sanitize=all")
   endif ()

src/CMakeLists.txt

@@ -66,7 +66,7 @@ set(LIBUNWIND_SOURCES
     ${LIBUNWIND_ASM_SOURCES})
 
 # Generate library list.
-if (C_SUPPORTS_NOSTDLIBXX_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
   add_link_flags_if_supported(-nostdlib++)
 else()
   if (LIBUNWIND_USE_COMPILER_RT)