Pass proper C++11 build flags to native optimizer CMake script.

tools/optimizer/CMakeLists.txt

@@ -5,6 +5,16 @@ project(asmjs_optimizer)
 file(GLOB sourceFiles *.cpp)
 file(GLOB headerFiles *.h)
 
+if (CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX OR CMAKE_C_COMPILER MATCHES ".*(gcc|clang|emcc).*" OR CMAKE_C_COMPILER_ID MATCHES ".*(GCC|Clang|emcc).*")
+	set(IS_GCC_LIKE TRUE)
+else()
+	set(IS_GCC_LIKE FALSE)
+endif()
+
+if (IS_GCC_LIKE)
+	set(cFlags "-std=c++11 -fno-exceptions -fno-rtti")
+endif()
+
 set(CMAKE_C_FLAGS     "${CMAKE_C_FLAGS} ${cFlags}")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${cFlags}")