Update CMakeLists.txt

CMakeLists.txt

@@ -21,19 +21,12 @@ if(NOT ${PREBUILD_RESULT} EQUAL 0)
     message(FATAL_ERROR "prebuild.py: ${PREBUILD_RESULT}")
 endif()
 
-if(MSVC)
-    add_compile_options("/utf-8")
-endif()
-
 if(EMSCRIPTEN)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fexceptions")
-    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fexceptions -O3")
 elseif(MSVC)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /EHsc /utf-8")
-    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /O2")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /EHsc /utf-8 /O2")
 else()
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fexceptions")
-    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O2")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fexceptions -O2")
 endif()
 
 include_directories(${CMAKE_CURRENT_LIST_DIR}/include)