Use CFLAGS as HOST_CFLAGS by default

Unless we're cross compiling, the HOST_CFLAGS should be the same as the
normal CFLAGS. This allows the x86 and x86_64 asm to be built correctly
with a native compiler using -m32/-m64.

Signed-off-by: Dan Nicholson <dbn.lists@gmail.com>

configs/default

@@ -23,6 +23,7 @@ HOST_CC = $(CC)
 CFLAGS = -O
 CXXFLAGS = -O
 LDFLAGS =
+HOST_CFLAGS = $(CFLAGS)
 GLU_CFLAGS = 
 
 # Compiler for building demos/tests/etc