[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, 4 insertions, 0 deletions

diff --git a/llgo/third_party/gofrontend/libgo/go/bytes/buffer.go b/llgo/third_party/gofrontend/libgo/go/bytes/buffer.go
index 46ca1d5ad3f..4db93867d9a 100644
--- a/llgo/third_party/gofrontend/libgo/go/bytes/buffer.go
+++ b/llgo/third_party/gofrontend/libgo/go/bytes/buffer.go
@@ -56,6 +56,10 @@ func (b *Buffer) String() string {
 // b.Len() == len(b.Bytes()).
 func (b *Buffer) Len() int { return len(b.buf) - b.off }
 
+// Cap returns the capacity of the buffer's underlying byte slice, that is, the
+// total space allocated for the buffer's data.
+func (b *Buffer) Cap() int { return cap(b.buf) }
+
 // Truncate discards all but the first n unread bytes from the buffer.
 // It panics if n is negative or greater than the length of the buffer.
 func (b *Buffer) Truncate(n int) {