[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, 11 insertions, 0 deletions

diff --git a/llgo/third_party/gofrontend/libgo/go/debug/dwarf/buf.go b/llgo/third_party/gofrontend/libgo/go/debug/dwarf/buf.go
index 53c46eb4b81..2ade0bd76ad 100644
--- a/llgo/third_party/gofrontend/libgo/go/debug/dwarf/buf.go
+++ b/llgo/third_party/gofrontend/libgo/go/debug/dwarf/buf.go
@@ -163,6 +163,17 @@ func (b *buf) addr() uint64 {
 	return 0
 }
 
+func (b *buf) unitLength() (length Offset, dwarf64 bool) {
+	length = Offset(b.uint32())
+	if length == 0xffffffff {
+		dwarf64 = true
+		length = Offset(b.uint64())
+	} else if length >= 0xfffffff0 {
+		b.error("unit length has reserved value")
+	}
+	return
+}
+
 func (b *buf) error(s string) {
 	if b.err == nil {
 		b.data = nil