all: move internal/x to vendor/golang.org/x and revendor using 'go mod vendor'

This also updates the vendored-in versions of several packages: 'go
mod vendor' selects a consistent version of each module, but we had
previously vendored an ad-hoc selection of packages.

Notably, x/crypto/hkdf was previously vendored in at a much newer
commit than the rest of x/crypto. Bringing the rest of x/crypto up to
that commit introduced an import of golang.org/x/sys/cpu, which broke
the js/wasm build, requiring an upgrade of x/sys to pick up CL 165749.

Updates #30228
Updates #30241
Updates #25822

Change-Id: I5b3dbc232b7e6a048a158cbd8d36137af1efb711
Reviewed-on: https://go-review.googlesource.com/c/go/+/164623
Reviewed-by: Filippo Valsorda <filippo@golang.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go
index 87739a510d..c31d36acae 100644
--- a/src/cmd/dist/build.go
+++ b/src/cmd/dist/build.go
@@ -192,6 +192,21 @@ func xinit() {
 
 	gogcflags = os.Getenv("BOOT_GO_GCFLAGS")
 
+	// Add -mod=vendor to GOFLAGS so that commands won't try to resolve go.mod
+	// files for vendored external modules.
+	// TODO(golang.org/issue/30240): If the vendor directory contains the go.mod
+	// files, this probably won't be necessary.
+	// TODO(golang.org/issue/26849): Escape spaces in GOFLAGS if needed.
+	goflags := strings.Fields(os.Getenv("GOFLAGS"))
+	for i, flag := range goflags {
+		if strings.HasPrefix(flag, "-mod=") {
+			goflags = append(goflags[0:i], goflags[i+1:]...)
+			break
+		}
+	}
+	goflags = append(goflags, "-mod=vendor")
+	os.Setenv("GOFLAGS", strings.Join(goflags, " "))
+
 	cc, cxx := "gcc", "g++"
 	if defaultclang {
 		cc, cxx = "clang", "clang++"