Go patch committed: Don't check invalid constant when lowering binary expr

[Ian Lance Taylor]

This patch by Chris Manghane changes the Go frontend to not check for
an invalid constant when lowering a binary expression.  This fixes
https://golang.org/issue/12615 .  Bootstrapped and ran Go testsuite on
x86_64-unknown-linux-gnu.  Committed to mainline.

Ian

Index: gcc/go/gofrontend/MERGE
===================================================================
--- gcc/go/gofrontend/MERGE     (revision 229096)
+++ gcc/go/gofrontend/MERGE     (working copy)
@@ -1,4 +1,4 @@
-302d8abbc499e28088d758ae8b2c024d8e50b9b3
+11e249a59e8c627fe9c2938c38e39cb1efefb1fb
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: gcc/go/gofrontend/expressions.cc
===================================================================
--- gcc/go/gofrontend/expressions.cc    (revision 229096)
+++ gcc/go/gofrontend/expressions.cc    (working copy)
@@ -4909,14 +4909,7 @@ Binary_expression::do_lower(Gogo* gogo,
            Numeric_constant nc;
            if (!Binary_expression::eval_constant(op, &left_nc, &right_nc,
                                                  location, &nc))
-              {
-                if (nc.is_invalid())
-                  {
-                    go_assert(saw_errors());
-                    return Expression::make_error(location);
-                  }
                 return this;
-              }
            return nc.expression(location);
          }
       }