Only update typar name when TyparStaticReq matches.

[nojaf]

As mentioned on Slack by Josua Jäger, there was a recent regression in the 7.0.400 SDK.
The fix for this is that we can't update the ident of the syntypar when ' doesn't match with ^.

[vzarytovskii]

/backport to release/dev17.7

[github-actions]

Started backporting to release/dev17.7: https://github.com/dotnet/fsharp/actions/runs/5952907769

[github-actions]

@vzarytovskii backporting to release/dev17.7 failed, the patch most likely resulted in conflicts:

$ git am --3way --ignore-whitespace --keep-non-patch changes.patch

Applying: Only update typar name when TyparStaticReq matches.
.git/rebase-apply/patch:66: trailing whitespace.
        FSharp """        
.git/rebase-apply/patch:101: trailing whitespace.
    FSharp """        
warning: 2 lines add whitespace errors.
Using index info to reconstruct a base tree...
M	src/Compiler/Checking/CheckDeclarations.fs
M	tests/FSharp.Compiler.ComponentTests/Signatures/TypeTests.fs
Falling back to patching base and 3-way merge...
Auto-merging tests/FSharp.Compiler.ComponentTests/Signatures/TypeTests.fs
Auto-merging src/Compiler/Checking/CheckDeclarations.fs
CONFLICT (content): Merge conflict in src/Compiler/Checking/CheckDeclarations.fs
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 Only update typar name when TyparStaticReq matches.
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!