Factor code stubs out of JITX86.

sourcepawn/jit/AMBuilder

@@ -31,6 +31,7 @@ library = setup(builder.compiler.StaticLibrary('sourcepawn'))
 library.sources += [
   'api.cpp',
   'code-allocator.cpp',
+  'code-stubs.cpp',
   'plugin-runtime.cpp',
   'compiled-function.cpp',
   'debug-trace.cpp',
@@ -40,7 +41,9 @@ library.sources += [
   'opcodes.cpp',
   'interpreter.cpp',
   'watchdog_timer.cpp',
+  'x86/code-stubs-x86.cpp',
   'x86/jit_x86.cpp',
+  'x86/x86-utils.cpp',
   'zlib/adler32.c',
   'zlib/compress.c',
   'zlib/crc32.c',