compiler: fix import of indirectly imported type alias

    
    We were looking for the " = " before the optional package name that
    appears for an indirect reference, but the exporter was putting it
    after.
    
    Test is https://golang.org/cl/70290.
    
    Reviewed-on: https://go-review.googlesource.com/70330

From-SVN: r253694

gcc/go/gofrontend/MERGE

-af46ad16dc34773877068393d331ac8ae34b2219
+44132970e4b6c1186036bf8eda8982fb6e905d6f
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

gcc/go/gofrontend/import.cc

@@ -756,13 +756,6 @@ Import::read_type()
 
   this->require_c_string(" ");
 
-  bool is_alias = false;
-  if (this->match_c_string("= "))
-    {
-      stream->advance(2);
-      is_alias = true;
-    }
-
   // The package name may follow.  This is the name of the package in
   // the package clause of that package.  The type name will include
   // the pkgpath, which may be different.
@@ -775,6 +768,13 @@ Import::read_type()
       this->require_c_string(" ");
     }
 
+  bool is_alias = false;
+  if (this->match_c_string("= "))
+    {
+      stream->advance(2);
+      is_alias = true;
+    }
+
   // Declare the type in the appropriate package.  If we haven't seen
   // it before, mark it as invisible.  We declare it before we read
   // the actual definition of the type, since the definition may refer