[clang] [llvm] Implement operand bundles for floating-point operations (PR #109798)

[Joshua Cranmer via llvm-commits]

================
@@ -2994,6 +2994,29 @@ A "convergencectrl" operand bundle is only valid on a ``convergent`` operation.
 When present, the operand bundle must contain exactly one value of token type.
 See the :doc:`ConvergentOperations` document for details.
 
+.. _ob_fpe:
+
+Floating-point Environment Operand Bundles
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+These operand bundles provide details on how the operation interacts with the
+:ref:`floating-point environment <_floatenv>`. There are two kinds of such
+operand bundles, which characterize interaction with floating-point control
+modes and status bits.
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jcranmer-intel wrote:

It seems to me that we also need the ability to represent that the instructions may depend on more than just the dynamic rounding mode for effect, for example denormal flushing bits, exception masking bits, or more exotic target-specific stuff (e.g., x87's precision control bit).

https://github.com/llvm/llvm-project/pull/109798