all: fix more typos

Change-Id: I978ad5e1800ebfceb78aaced438331a8341715d4
Reviewed-on: https://go-review.googlesource.com/c/tools/+/194697
Reviewed-by: Toshihiro Shiino <shiino.toshihiro@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/go/pointer/gen.go b/go/pointer/gen.go
index a111175..f2a5171 100644
--- a/go/pointer/gen.go
+++ b/go/pointer/gen.go
@@ -512,7 +512,7 @@
 	a.addressOf(instr.Type(), a.valueNode(z), w) //  z = &w
 }
 
-// genBuiltinCall generates contraints for a call to a built-in.
+// genBuiltinCall generates constraints for a call to a built-in.
 func (a *analysis) genBuiltinCall(instr ssa.CallInstruction, cgn *cgnode) {
 	call := instr.Common()
 	switch call.Value.(*ssa.Builtin).Name() {