[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, 13 insertions, 2 deletions

diff --git a/llgo/third_party/gofrontend/libgo/go/bytes/bytes.go b/llgo/third_party/gofrontend/libgo/go/bytes/bytes.go
index 7634707b3cb..b86824087e5 100644
--- a/llgo/third_party/gofrontend/libgo/go/bytes/bytes.go
+++ b/llgo/third_party/gofrontend/libgo/go/bytes/bytes.go
@@ -23,7 +23,7 @@ func equalPortable(a, b []byte) bool {
 	return true
 }
 
-// explode splits s into a slice of UTF-8 sequences, one per Unicode character (still slices of bytes),
+// explode splits s into a slice of UTF-8 sequences, one per Unicode code point (still slices of bytes),
 // up to a maximum of n byte slices. Invalid UTF-8 sequences are chopped into individual bytes.
 func explode(s []byte, n int) [][]byte {
 	if n <= 0 {
@@ -47,6 +47,7 @@ func explode(s []byte, n int) [][]byte {
 }
 
 // Count counts the number of non-overlapping instances of sep in s.
+// If sep is an empty slice, Count returns 1 + the number of Unicode code points in s.
 func Count(s, sep []byte) int {
 	n := len(sep)
 	if n == 0 {
@@ -137,6 +138,16 @@ func LastIndex(s, sep []byte) int {
 	return -1
 }
 
+// LastIndexByte returns the index of the last instance of c in s, or -1 if c is not present in s.
+func LastIndexByte(s []byte, c byte) int {
+	for i := len(s) - 1; i >= 0; i-- {
+		if s[i] == c {
+			return i
+		}
+	}
+	return -1
+}
+
 // IndexRune interprets s as a sequence of UTF-8-encoded Unicode code points.
 // It returns the byte index of the first occurrence in s of the given rune.
 // It returns -1 if rune is not present in s.
@@ -442,7 +453,7 @@ func isSeparator(r rune) bool {
 // Title returns a copy of s with all Unicode letters that begin words
 // mapped to their title case.
 //
-// BUG: The rule Title uses for word boundaries does not handle Unicode punctuation properly.
+// BUG(rsc): The rule Title uses for word boundaries does not handle Unicode punctuation properly.
 func Title(s []byte) []byte {
 	// Use a closure here to remember state.
 	// Hackish but effective. Depends on Map scanning in order and calling