Recreate the size SDNode instead of reusing the old one in the x86
memcpy lowering code; this ensures that the size node has the desired
result type. This fixes a regression from r49572 with @llvm.memcpy.i64
on x86-32.

llvm-svn: 49761
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 38e6342..d8eaee7 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -4731,7 +4731,7 @@
       default:  // Byte aligned
         AVT = MVT::i8;
         ValReg = X86::AL;
-        Count = Size;
+        Count = DAG.getIntPtrConstant(SizeVal);
         break;
     }
 
@@ -4746,7 +4746,7 @@
     InFlag = Chain.getValue(1);
   } else {
     AVT = MVT::i8;
-    Count  = Size;
+    Count  = DAG.getIntPtrConstant(SizeVal);
     Chain  = DAG.getCopyToReg(Chain, X86::AL, Src, InFlag);
     InFlag = Chain.getValue(1);
   }