[spirv] Support UAbs intrinsic function.

tools/clang/lib/SPIRV/SpirvEmitter.cpp

@@ -6460,6 +6460,7 @@ SpirvEmitter::processIntrinsicCallExpr(const CallExpr *callExpr) {
     INTRINSIC_SPIRV_OP_CASE(fwidth, Fwidth, true);
     INTRINSIC_SPIRV_OP_CASE(reversebits, BitReverse, false);
     INTRINSIC_OP_CASE(round, Round, true);
+    INTRINSIC_OP_CASE(uabs, SAbs, true);
     INTRINSIC_OP_CASE_INT_FLOAT(abs, SAbs, FAbs, true);
     INTRINSIC_OP_CASE(acos, Acos, true);
     INTRINSIC_OP_CASE(asin, Asin, true);