[clang] Fix #173673 assertion "Output operand lower bound is not zero" with asm output operand with '+Kr' constarint (PR #175470)

[Ulrich Weigand via cfe-commits]

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@@ -1131,6 +1131,7 @@ class TargetInfo : public TransferrableTargetInfo,
       CI_HasMatchingInput = 0x08,  // This output operand has a matching input.
       CI_ImmediateConstant = 0x10, // This operand must be an immediate constant
       CI_EarlyClobber = 0x20,      // "&" output constraint (early clobber).
+      CI_CCOutputOperand = 0x40,   // "=@cc" sets CC, Flag output operand.
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uweigand wrote:

As the feature is now intended to support output operand bounds in general, the name should not refer to "CC" at all.   This should simply be something like `CC_OutputOperandBounds`.

https://github.com/llvm/llvm-project/pull/175470