Bundle operands to specify denormal modes
Two new operands are now supported in the "fp.control" operand bundle:
* "denorm.in=xxx" - specifies the inpot denormal mode.
* "denorm.out=xxx" - specifies the output denormal mode.
Here xxx must be one of the following values:
* "ieee" - preserve denormals.
* "zero" - flush to zero preserving sign.
* "pzero" - flush to positive zero.
* "dyn" - mode is dynamically read from a control register.
These values align those permitted in the "denormal-fp-math" function
attribute.
