#line 1 "not-int-const"
	void __cgo_f_1_3(void) { enum { __cgo_undefined__3 = (foo)*1 }; }
	#line 1 "not-num-const"
	void __cgo_f_1_4(void) { static const double __cgo_undefined__4 = (foo); }
	#line 1 "not-str-lit"
	void __cgo_f_1_5(void) { static const char __cgo_undefined__5[] = (foo); }

This program will not compile, but cgo can use the presence or absence
of an error message on a given line to deduce the information it

The same assembler is used for all target operating systems and architectures.
The GOOS and GOARCH environment variables set the desired target.

Flags:

	-D name[=value]
		Predefine symbol name with an optional simple value.
		Can be repeated to define multiple symbols.
	-I dir1 -I dir2
		Search for #include files in dir1, dir2, etc,
		after consulting $GOROOT/pkg/$GOOS_$GOARCH.
	-S