[libffi] Check return value of execute_process()

To avoid hiding errors, the return values of the execute_process()
commands should be checked and a fatal error should be issued.

ports/libffi/CMakeLists.txt

@@ -120,17 +120,27 @@ macro(add_assembly ASMFILE)
             COMMAND ${CMAKE_C_COMPILER} /nologo /EP /I. /Iinclude /I${CMAKE_CURRENT_SOURCE_DIR}/include "${ASMFILE_FULL}"
             WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
             OUTPUT_FILE ${ARCH_ASM_NAME}.asm
+            RESULT_VARIABLE retcode
         )
 
+        if(NOT ${retcode} STREQUAL "0")
+            message(FATAL_ERROR "Unable to assemble, exit code: '${retcode}'.")
+        endif()
+
         # Produced *.asm file could be just added to sources.
         # It works in x64 mode, but for some strange reason MASM returns error code when in x86,
         # (even though it didn't report any errors and correctly generated object file)
         # which in turn causes MSBUILD to stop.
         execute_process(
             COMMAND ${ARCH_ASSEMBLER} ${ARCH_ASM_NAME}.asm
             WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+            RESULT_VARIABLE retcode
         )
 
+        if(NOT ${retcode} STREQUAL "0")
+            message(FATAL_ERROR "Unable to compile assembly, exit code: '${retcode}'.")
+        endif()
+
         list(APPEND FFI_SOURCES ${CMAKE_BINARY_DIR}/${ARCH_ASM_NAME}.obj)
     else()
         list(APPEND FFI_SOURCES ${ASMFILE})

ports/libffi/CONTROL

@@ -1,4 +1,4 @@
 Source: libffi
-Version: 3.3-1
+Version: 3.3-2
 Homepage: https://github.com/libffi/libffi
 Description: Portable, high level programming interface to various calling conventions