Pass shufflevector indices as int instead of unsigned.

No functionality change intended.
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 87f5210..f4832ef 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -11747,7 +11747,7 @@
     // Splat the 8-bits of immediate 4 times to help the loop wrap around.
     Imm = (Imm & 0xff) * 0x01010101;
 
-    uint32_t Indices[16];
+    int Indices[16];
     for (unsigned l = 0; l != NumElts; l += NumLaneElts) {
       for (unsigned i = 0; i != NumLaneElts; ++i) {
         unsigned Index = Imm % NumLaneElts;