Windows: Fix libSDLmain compilation

Ensure that SDL_CFLAGS is passed to LOCAL_CFLAGS when building the
libSDLmain libraries. Otherwise, on Windows, the NO_STDIO_REDIRECT
macro is not defined which prevents the emulator binary from dumping
its output to the command-line as it should (instead, stdout.txt and
stderr.txt were used).

Change-Id: I4e0776dbdae69594475dd77262c9a6848af8fffc
diff --git a/distrib/sdl-1.2.15/sources.make b/distrib/sdl-1.2.15/sources.make
index 76e57f8..ea0a5e9 100644
--- a/distrib/sdl-1.2.15/sources.make
+++ b/distrib/sdl-1.2.15/sources.make
@@ -265,6 +265,7 @@
 
 $(call start-emulator-library,emulator_libSDLmain)
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/include
+LOCAL_CFLAGS += $(SDL_CFLAGS)
 LOCAL_SRC_FILES := $(SDLMAIN_SOURCES)
 $(call end-emulator-library)