Fix SDISel lowering of zeroinitializer and undef to use ComputeValueVTs.

This allows it to work correctly on nested aggregate values.
This fixes PR2625.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54330 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/Generic/pr2625.ll

@@ -0,0 +1,17 @@
+; RUN: llvm-as < %s | llc
+; PR2625
+
+define i32 @main({ i32, { i32 } }*) {
+entry:
+        %state = alloca { i32, { i32 } }*               ; <{ i32, { i32 } }**> [#uses=2]
+        store { i32, { i32 } }* %0, { i32, { i32 } }** %state
+        %retval = alloca i32            ; <i32*> [#uses=2]
+        store i32 0, i32* %retval
+        load { i32, { i32 } }** %state          ; <{ i32, { i32 } }*>:1 [#uses=1]
+        store { i32, { i32 } } zeroinitializer, { i32, { i32 } }* %1
+        br label %return
+
+return:         ; preds = %entry
+        load i32* %retval               ; <i32>:2 [#uses=1]
+        ret i32 %2
+}