Rewrite multiple return value handling in SCCP. Before, the -sccp pass

would turn every getresult instruction into undef.  This helps with
rdar://5778210


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50140 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/SCCP/2008-04-22-multiple-ret-sccp.ll

@@ -0,0 +1,11 @@
+; RUN: llvm-as < %s  | opt -sccp | llvm-dis | grep {ret i32 %Z}
+; rdar://5778210
+
+declare {i32, i32} @bar(i32 %A) 
+
+define i32 @foo() {
+	%X = call {i32, i32} @bar(i32 17)
+        %Y = getresult {i32, i32} %X, 0
+	%Z = add i32 %Y, %Y
+	ret i32 %Z
+}