This adds support for the cfp-except and cfp-round operand bundles. These bundles can be tagged on to floating-point intrinsics to specify a non-default floating environment.
The first application, we are preparing with this patch, is to support non-default fp environments in VP intrinsics (eg llvm.vp.fadd). However, constrained fp bundles could replace all redundant intrinsics that are just another intrinsic plus metadata params for the fp environment (eg llvm.experimental.constrained.sqrt).
This patch won't be committed before floating-point VP intrinsics are in (unless people would like to use these bundles right away for constrained fp, of course).