compiled with the OS-native compiler.
	.s, .S, .sx
		Assembler source files.
		If the package uses cgo or SWIG, these will be assembled with the
		OS-native assembler (typically gcc (sic)); otherwise they
		will be assembled with the Go assembler.
	.swig, .swigcxx
		SWIG definition files.
	.syso
		System object files.

Files of each of these types except .syso may contain build

//		compiled with the OS-native compiler.
//	.s, .S, .sx
//		Assembler source files.
//		If the package uses cgo or SWIG, these will be assembled with the
//		OS-native assembler (typically gcc (sic)); otherwise they
//		will be assembled with the Go assembler.
//	.swig, .swigcxx
//		SWIG definition files.
//	.syso
//		System object files.
//