compiler: avoid a couple of compiler crashes

    
    These came up while building 1.14beta1 while the code was still invalid.
    The policy is to not bother committing invalid test cases that cause
    compiler crashes.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/213537

From-SVN: r279956

gcc/go/gofrontend/MERGE

-9163fa28b89222cd851c0d24bd6a1384d1379c55
+d0a102eea2262e3fca89b1eb342fd03328c4aa16
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

gcc/go/gofrontend/expressions.cc

@@ -11766,10 +11766,17 @@ Call_expression::do_add_conversions()
   Typed_identifier_list::const_iterator pp = fntype->parameters()->begin();
   bool is_interface_method =
     this->fn_->interface_field_reference_expression() != NULL;
+  size_t argcount = this->args_->size();
   if (!is_interface_method && fntype->is_method())
     {
       // Skip the receiver argument, which cannot be interface.
       pa++;
+      argcount--;
+    }
+  if (argcount != fntype->parameters()->size())
+    {
+      go_assert(saw_errors());
+      return;
     }
   for (; pa != this->args_->end(); ++pa, ++pp)
     {
@@ -11895,6 +11902,8 @@ Call_expression::is_erroneous_call()
 Type*
 Call_expression::do_type()
 {
+  if (this->is_error_expression())
+    return Type::make_error_type();
   if (this->type_ != NULL)
     return this->type_;