fix Issue 12009 - local import and "unable to resolve forward referen…

…ce" error

`Module::semantic2` could be invoked from local imports, even when some
local symbol semantics are not yet completed.

src/mars.c

@@ -1563,6 +1563,15 @@ Language changes listed by -transition=id:\n\
 
     Module::dprogress = 1;
     Module::runDeferredSemantic();
+    if (Module::deferred.dim)
+    {
+        for (size_t i = 0; i < Module::deferred.dim; i++)
+        {
+            Dsymbol *sd = Module::deferred[i];
+            sd->error("unable to resolve forward reference in definition");
+        }
+        fatal();
+    }
 
     // Do pass 2 semantic analysis
     for (size_t i = 0; i < modules.dim; i++)

src/module.c

@@ -758,16 +758,6 @@ void Module::semantic()
 
 void Module::semantic2()
 {
-    if (deferred.dim)
-    {
-        for (size_t i = 0; i < deferred.dim; i++)
-        {
-            Dsymbol *sd = deferred[i];
-
-            sd->error("unable to resolve forward reference in definition");
-        }
-        return;
-    }
     //printf("Module::semantic2('%s'): parent = %p\n", toChars(), parent);
     if (semanticRun != PASSsemanticdone)       // semantic() not completed yet - could be recursive call
         return;

test/compilable/test12009.d

@@ -0,0 +1,36 @@
+struct RefCounted(T)
+{
+    struct RefCountedStore
+    {
+        private struct Impl
+        {
+            T _payload;
+        }
+
+        private Impl* _store;
+    }
+    RefCountedStore _refCounted;
+
+    ~this()
+    {
+        import core.stdc.stdlib : free;
+    }
+}
+
+struct GroupBy(R)
+{
+    struct SharedInput
+    {
+        Group unused;
+    }
+
+    struct Group
+    {
+        private RefCounted!SharedInput _allGroups;
+    }
+}
+
+void main()
+{
+    GroupBy!(int[]) g1;
+}