compiler: Check for EOF in malformed signatures.

    
    When parsing a malformed function declaration with invalid parameters,
    gccgo would infinitely loop looking for the end of the function
    declaration.
    
    Fixes golang/go#11530, golang/go#11531.
    
    Reviewed-on: https://go-review.googlesource.com/13065

From-SVN: r226795

gcc/go/gofrontend/MERGE

-3b590ff53700963c1b8207a78594138e6a4e47f4
+55175f7ee0db2c1e68423216d7744be80071ed6c
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

gcc/go/gofrontend/parse.cc

@@ -1045,7 +1045,8 @@ Parse::parameter_decl(bool parameters_have_names,
 	    {
 	      *mix_error = true;
 	      while (!this->peek_token()->is_op(OPERATOR_COMMA)
-		     && !this->peek_token()->is_op(OPERATOR_RPAREN))
+		     && !this->peek_token()->is_op(OPERATOR_RPAREN)
+                     && !this->peek_token()->is_eof())
 		this->advance_token();
 	    }
 	}