Allow external builds to use non-gnu compilers

JerryScript-DCO-1.0-Signed-off-by: François Baldassari francois@pebble.com

CMakeLists.txt

@@ -20,7 +20,7 @@ project (Jerry C ASM)
  string(TOUPPER "${PLATFORM}" PLATFORM)
 
 # Compiler configuration
- if(NOT ("${PLATFORM}" STREQUAL "DARWIN"))
+ if(NOT (("${PLATFORM}" STREQUAL "DARWIN") OR ("${PLATFORM}" STREQUAL "EXTERNAL")))
   if(NOT CMAKE_COMPILER_IS_GNUCC)
    message(FATAL_ERROR "gcc compiler is required")
   endif()