Update EMCC_SUFFIX instead of trying to manually determine which platform we are cross compiling from (#683)

Author: mcbarton

cmake/modules/GoogleTest.cmake

@@ -20,20 +20,11 @@ endif()
 
 include(ExternalProject)
 if (EMSCRIPTEN)
-  if (CMAKE_C_COMPILER MATCHES ".bat")
-    set(config_cmd emcmake.bat cmake)
-    if(CMAKE_GENERATOR STREQUAL "Ninja")
-      set(build_cmd emmake.bat ninja)
-    else()
-      set(build_cmd emmake.bat make)
-    endif()
+  set(config_cmd emcmake${EMCC_SUFFIX} cmake)
+  if(CMAKE_GENERATOR STREQUAL "Ninja")
+    set(build_cmd emmake${EMCC_SUFFIX} ninja)
   else()
-    set(config_cmd emcmake cmake)
-    if(CMAKE_GENERATOR STREQUAL "Ninja")
-      set(build_cmd emmake ninja)
-    else()
-      set(build_cmd emmake make)
-    endif()
+    set(build_cmd emmake${EMCC_SUFFIX} make)
   endif()
 else()
   set(config_cmd ${CMAKE_COMMAND})