[llvm] Reland "[ValueTracking] Compute knownbits from known fp classes" (PR #92084)

[via llvm-commits]

mikaelholmen wrote:

Hi @dtcxzyw 
The following starts crashing with this patch:
```
opt -passes="instcombine" bbi-95530.ll -o /dev/null
```
It fails with
```
opt: ../lib/Analysis/ValueTracking.cpp:1152: void computeKnownBitsFromOperator(const llvm::Operator *, const llvm::APInt &, llvm::KnownBits &, unsigned int, const llvm::SimplifyQuery &): Assertion `!Known.hasConflict() && "Bits known to be one AND zero?"' failed.
```
[bbi-95530.ll.gz](https://github.com/llvm/llvm-project/files/15330187/bbi-95530.ll.gz)


https://github.com/llvm/llvm-project/pull/92084