CMake: use response files

As Mbed OS is built as whole, we have long paths again. This is known issue with windows. To fix the paths, we need to use response files.

Ninja is special, needs to be forced to use long paths.

Author: 0xc0170

cmake/toolchain.cmake

@@ -76,3 +76,22 @@ set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "" CACHE STRING "" FORCE)
 set(CMAKE_ASM_FLAGS_DEBUG "" CACHE STRING "" FORCE)
 set(CMAKE_ASM_FLAGS_RELEASE "" CACHE STRING "" FORCE)
 set(CMAKE_ASM_FLAGS_RELWITHDEBINFO "" CACHE STRING "" FORCE)
+
+# Use response files always
+set(CMAKE_ASM_USE_RESPONSE_FILE_FOR_INCLUDES 1)
+set(CMAKE_C_USE_RESPONSE_FILE_FOR_INCLUDES 1)
+set(CMAKE_CXX_USE_RESPONSE_FILE_FOR_INCLUDES 1)
+
+set(CMAKE_ASM_USE_RESPONSE_FILE_FOR_OBJECTS 1)
+set(CMAKE_C_USE_RESPONSE_FILE_FOR_OBJECTS 1)
+set(CMAKE_CXX_USE_RESPONSE_FILE_FOR_OBJECTS 1)
+
+set(CMAKE_ASM_USE_RESPONSE_FILE_FOR_LIBRARIES 1)
+set(CMAKE_C_USE_RESPONSE_FILE_FOR_LIBRARIES 1)
+set(CMAKE_CXX_USE_RESPONSE_FILE_FOR_LIBRARIES 1)
+
+# Ninja requires to be forced for response files
+if ("${CMAKE_GENERATOR}" MATCHES "Ninja")
+    set(CMAKE_NINJA_FORCE_RESPONSE_FILE 1 CACHE INTERNAL "") 
+endif()
+