Fix RawVarDecl double codegen bug. Thanks to downs for the testcase.

gen/llvmhelpers.cpp

@@ -1332,6 +1332,10 @@ LLValue* DtoRawVarDeclaration(VarDeclaration* var)
 
     // we don't handle aliases either
     assert(!var->aliassym);
+        
+    // if this already has storage, it must've been handled already
+    if (var->ir.irLocal && var->ir.irLocal->value)
+        return var->ir.irLocal->value;
 
     // referenced by nested function?
 #if DMDV2

tests/mini/compile_rawvardeclinfinally.d

@@ -0,0 +1 @@
+void foo() { void delegate()[] bar; try {} finally { foreach (dg; bar) dg(); } }