14de5a2a4f
This change contains the initial support of FastMath flag in complex dialect. Similar to what we did in [Arith dialect](https://reviews.llvm.org/rGb56e65d31825fe4a1ae02fdcbad58bb7993d63a7), `fastmath` attributes in the complex dialect are directly mapped to the corresponding LLVM fastmath flags. In this diff, - Definition of FastMathAttr as a custom attribute in the Complex dialect that inherits from the EnumAttr class. - Definition of ComplexFastMathInterface, which is an interface that is implemented by operations that have a complex::fastmath attribute. - Declaration of a default-valued fastmath attribute for unary and arithmetic operations in the Complex dialect. - Conversion code to lower arithmetic fastmath flags to LLVM fastmath flags NOT in this diff (but planned and progressively implemented): - Documentation of flag meanings - Support the fastmath flag conversion to Arith dialect - Folding/rewrite implementations that are enabled by fastmath flags (although it's the original motivation to support the flag) RFC: https://discourse.llvm.org/t/rfc-fastmath-flags-support-in-complex-dialect/71981 Reviewed By: kiranchandramohan Differential Revision: https://reviews.llvm.org/D156310