[llvm] [Support][ValueTraking] Improve KnownFPClass for fadd. Handle infinity signs and strict sign cases (PR #190559)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 133067 tests passed
* 3061 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### LLVM
<details>
<summary>LLVM.Transforms/InstSimplify/known-never-nan.ll</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
c:\_work\llvm-project\llvm-project\build\bin\opt.exe < C:\_work\llvm-project\llvm-project\llvm\test\Transforms\InstSimplify\known-never-nan.ll -S -passes=instsimplify | c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe C:\_work\llvm-project\llvm-project\llvm\test\Transforms\InstSimplify\known-never-nan.ll
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\opt.exe' -S -passes=instsimplify
# note: command had no output on stdout or stderr
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe' 'C:\_work\llvm-project\llvm-project\llvm\test\Transforms\InstSimplify\known-never-nan.ll'
# .---command stderr------------
# | C:\_work\llvm-project\llvm-project\llvm\test\Transforms\InstSimplify\known-never-nan.ll:343:15: error: CHECK-NEXT: expected string not found in input
# | ; CHECK-NEXT: [[OP:%.*]] = uitofp i1024 [[ARG0:%.*]] to double
# |               ^
# | <stdin>:158:27: note: scanning from here
# | define i1 @uitofp_add_big(i1024 %arg0) {
# |                           ^
# | 
# | Input file: <stdin>
# | Check file: C:\_work\llvm-project\llvm-project\llvm\test\Transforms\InstSimplify\known-never-nan.ll
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |           .
# |           .
# |           .
# |         153:  
# |         154: define i1 @uitofp_add(i32 %arg0) { 
# |         155:  ret i1 true 
# |         156: } 
# |         157:  
# |         158: define i1 @uitofp_add_big(i1024 %arg0) { 
# | next:343                               X~~~~~~~~~~~~~~ error: no match found
# |         159:  ret i1 true 
# | next:343     ~~~~~~~~~~~~~
# |         160: } 
# | next:343     ~~
# |         161:  
# | next:343     ~
# |         162: define i1 @fpext(float %arg0) { 
# | next:343     ~~~~~~~~~~~~~~~~~
# |         163:  ret i1 false 
# |           .
# |           .
# |           .
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/190559