Fix PR3468: a crash when constant folding a bitcast of

i80 to x86 long double (this was presumably generated
by sroa).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63730 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/InstCombine/2009-02-04-FPBitcast.ll

@@ -0,0 +1,7 @@
+; RUN: llvm-as < %s | opt -instcombine
+; PR3468
+
+define x86_fp80 @cast() {
+	%tmp = bitcast i80 0 to x86_fp80		; <x86_fp80> [#uses=1]
+	ret x86_fp80 %tmp
+}