//		The file is a JSON struct with a single field, named 'Replace', that
//		maps each disk file path (a string) to its backing file path, so that
//		a build will run as if the disk file path exists with the contents
//		given by the backing file paths, or as if the disk file path does not
//		exist if its backing file path is empty. Support for the -overlay flag
//		has some limitations: importantly, cgo files included from outside the

		go func() {
			defer wg.Done()

			contentLen := fmt.Sprintf("Content-Length: %d", test.contentLength)
			if test.chunked {
				contentLen = "Transfer-Encoding: chunked"
			}
			_, err := fmt.Fprintf(conn, "POST /?readbody=%v HTTP/1.1\r\n"+
				"Connection: close\r\n"+
				"%s\r\n"+
				"Expect: %s\r\nHost: foo\r\n\r\n",
				test.readBody, contentLen, test.expectation)
			if err != nil {

	if p.UsesCgo() || p.UsesSwig() {
		if pcCFLAGS, pcLDFLAGS, err = b.getPkgConfigFlags(a); err != nil {
			return
		}
	}

	// Compute overlays for .c/.cc/.h/etc. and if there are any overlays
	// put correct contents of all those files in the objdir, to ensure
	// the correct headers are included. nonGoOverlay is the overlay that
	// points from nongo files to the copied files in objdir.

	ctxt.tramps = append(ctxt.tramps, s.Sym())
	if *FlagDebugTramp > 0 && ctxt.Debugvlog > 0 {
		ctxt.Logf("trampoline %s inserted\n", s.Name())
	}
}

// compressSyms compresses syms and returns the contents of the
// compressed section. If the section would get larger, it returns nil.
func compressSyms(ctxt *Link, syms []loader.Sym) []byte {
	ldr := ctxt.loader
	var total int64
	for _, sym := range syms {