[clang] [llvm] Add support for flag output operand "=@cc" for SystemZ. (PR #125970)

[Ulrich Weigand via cfe-commits]

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@@ -0,0 +1,939 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; Test Flag Output Operands with 14 combinations of CCMASK and optimizations
+; for AND  for 3 three different functions, including two tests from heiko.
+; This test checks combinations of EQUAL(==) and NOT EQUAL (!=) operator. e.g.
+; CC == 0 && CC != 1 && CC != 2 and  CC == 0 && CC == 2 && CC != 3.
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uweigand wrote:

Again, common optimizers will recognize that `CC == 0 && CC != 1` is just the same as `CC == 0`.  This doesn't do anything in this file.

https://github.com/llvm/llvm-project/pull/125970