Fix broken simplecpp builds with libc++

Author: pfultz2

externals/simplecpp/CMakeLists.txt

@@ -3,6 +3,7 @@ file(GLOB srcs "*.cpp")
 
 add_library(simplecpp ${srcs} ${hdrs})
 target_dll_compile_definitions(simplecpp EXPORT SIMPLECPP_EXPORT IMPORT SIMPLECPP_IMPORT)
+target_compile_definitions(simplecpp PUBLIC SIMPLECPP_TOKENLIST_ALLOW_PTR)
 
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     target_compile_options_safe(simplecpp -Wno-zero-as-null-pointer-constant)