[llgo] Roll gofrontend forward

Switch gofrontend to using go.googlesource.com, and
update to 81eb6a3f425b2158c67ee32c0cc973a72ce9d6be.

There are various changes required to update to the
go 1.5 runtime:

typemap.go is changed to accommodate the change in representation for equal/hash algorithms, and the removal of the zero value/type.
CMakeLists.txt is updated to add the build tree to the package search path, so internal packages, which are not installed, are found.
various files changes due to removal of __go_new_nopointers; the same change as in D11863, but with NoUnwindAttribute added to the added runtime functions which are called with "callOnly".
minor cleanups in ssa.go while investigating issues with unwinding/panic handling.

Differential Revisision: http://reviews.llvm.org/D15188

llvm-svn: 263536

1 files changed, 3 insertions, 0 deletions

diff --git a/llgo/third_party/gofrontend/libgo/go/crypto/cipher/cipher.go b/llgo/third_party/gofrontend/libgo/go/crypto/cipher/cipher.go
index 67afdb1e057..7d27fde61d8 100644
--- a/llgo/third_party/gofrontend/libgo/go/crypto/cipher/cipher.go
+++ b/llgo/third_party/gofrontend/libgo/go/crypto/cipher/cipher.go
@@ -29,6 +29,9 @@ type Block interface {
 type Stream interface {
 	// XORKeyStream XORs each byte in the given slice with a byte from the
 	// cipher's key stream. Dst and src may point to the same memory.
+	// If len(dst) < len(src), XORKeyStream should panic. It is acceptable
+	// to pass a dst bigger than src, and in that case, XORKeyStream will
+	// only update dst[:len(src)] and will not touch the rest of dst.
 	XORKeyStream(dst, src []byte)
 }