mcize lcomm, simplify .comm, extend both to support 64-bit sizes.

llvm-svn: 94299
diff --git a/llvm/lib/MC/MCNullStreamer.cpp b/llvm/lib/MC/MCNullStreamer.cpp
index 46da4c4..7c219b32 100644
--- a/llvm/lib/MC/MCNullStreamer.cpp
+++ b/llvm/lib/MC/MCNullStreamer.cpp
@@ -39,8 +39,9 @@
 
     virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
 
-    virtual void EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
+    virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                   unsigned ByteAlignment) {}
+    virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {}
 
     virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
                               unsigned Size = 0, unsigned ByteAlignment = 0) {}