cmake HAVE___GLIBCXX__ examples

cmake HAVE_GLIBCXX examples

swiftlang/swift Runtimes/Overlay/Cxx/CMakeLists.txt :4

check_symbol_exists(__GLIBCXX__ "version" HAVE___GLIBCXX__)

swiftlang/swift Runtimes/Overlay/Cxx/std/CMakeLists.txt :25

target_link_libraries(swiftCxxStdlib PRIVATE
  $<$<BOOL:${HAVE___GLIBCXX__}>:libstdcxx>
  $<$<NOT:$<PLATFORM_ID:Darwin>>:cxxshim>
  swiftCxx
  swiftCore
  swift_Builtin_float
  $<$<PLATFORM_ID:Android>:SwiftAndroid>
  $<$<PLATFORM_ID:Windows>:ClangModules>)