crypto/sha1, crypto/sha256: add go:noescape annotations

Additions to:
https://go-review.googlesource.com/c/go/+/61570
https://go-review.googlesource.com/c/go/+/61550

Change-Id: Id89e1119333a8721cb9720a04a01dab1f2705fa9
Reviewed-on: https://go-review.googlesource.com/77591
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/crypto/sha1/sha1block_arm64.go

@@ -15,7 +15,7 @@ var k = []uint32{
 
 var hasSHA1 = cpu.ARM64.HasSHA1
 
-
+//go:noescape
 func sha1block(h []uint32, p []byte, k []uint32)
 
 func block(dig *digest, p []byte) {

src/crypto/sha256/sha256block_arm64.go

@@ -10,6 +10,7 @@ var k = _K
 
 var hasSHA2 = cpu.ARM64.HasSHA2
 
+//go:noescape
 func sha256block(h []uint32, p []byte, k []uint32)
 
 func block(dig *digest, p []byte) {