Runtimes: correct generator expression language spelling

This corrects the compile language check in the generator expression to
add the missing `X`.

Author: compnerd

Runtimes/Core/core/CMakeLists.txt

@@ -312,7 +312,7 @@ target_compile_options(swiftCore PRIVATE
 target_compile_definitions(swiftCore PRIVATE
   $<$<BOOL:${SwiftCore_ENABLE_REFLECTION}>:-DSWIFT_ENABLE_REFLECTION>
   $<$<BOOL:${SwiftCore_ENABLE_COMPACT_ABSOLUTE_FUNCTION_POINTERS}>:-DSWIFT_COMPACT_ABSOLUTE_FUNCTION_POINTER>
-  $<$<COMPILE_LANGUAGE:C,CX>:-DSWIFT_TARGET_LIBRARY_NAME=swiftCore>)
+  $<$<COMPILE_LANGUAGE:C,CXX>:-DSWIFT_TARGET_LIBRARY_NAME=swiftCore>)
 target_compile_options(swiftCore PRIVATE
   "$<$<AND:$<BOOL:${BUILD_SHARED_LIBS}>,$<COMPILE_LANGUAGE:Swift>>:SHELL:-Xcc -DswiftCore_EXPORTS>")