Go patch committed: Type check parameters in sink function declaration

[Ian Lance Taylor]

This patch by Chris Manghane fixes the Go frontend to type check
function parameters in a sink function declaration, as in func _(int).
This fixes https://golang.org/issue/11535 .  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 227039)
+++ gcc/go/gofrontend/MERGE     (working copy)
@@ -1,4 +1,4 @@
-cc7303c97b232ea979cab950d95aaf76c4e0f5b5
+81810917af7ba19e1f9f8efc8b1989f7d6419d30
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: gcc/go/gofrontend/parse.cc
===================================================================
--- gcc/go/gofrontend/parse.cc  (revision 226846)
+++ gcc/go/gofrontend/parse.cc  (working copy)
@@ -2305,8 +2305,20 @@ Parse::function_decl(bool saw_nointerfac
 
   if (!this->peek_token()->is_op(OPERATOR_LCURLY))
     {
-      if (named_object == NULL && !Gogo::is_sink_name(name))
+      if (named_object == NULL)
        {
+          // Function declarations with the blank identifier as a name are
+          // mostly ignored since they cannot be called.  We make an object
+          // for this declaration for type-checking purposes.
+          if (Gogo::is_sink_name(name))
+            {
+              static int count;
+              char buf[30];
+              snprintf(buf, sizeof buf, ".$sinkfndecl%d", count);
+              ++count;
+              name = std::string(buf);
+            }
+
          if (fntype == NULL
               || (expected_receiver && rec == NULL))
            this->gogo_->add_erroneous_name(name);