cmd/compile/internal/syntax: remove dead type declaration

Change-Id: I8a3ce0fa513ff943009c5669531132cd23ecf155
Reviewed-on: https://go-review.googlesource.com/33870Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/compile/internal/syntax/parser.go

@@ -26,8 +26,6 @@ type parser struct {
 	indent []byte // tracing support
 }
 
-type parserError string // for error recovery if no error handler was installed
-
 func (p *parser) init(src io.Reader, errh ErrorHandler, pragh PragmaHandler) {
 	p.scanner.init(src, errh, pragh)