Build a project's TcGlobals with its own path map when the framework imports are cached

[xperiandri]

Description

FrameworkImportsCache caches the framework TcImports together with the TcGlobals built for the first project of a framework set. Its key — framework assemblies, primary assembly, target framework directories, compiler binaries directory, import-reuse key — does not include the path map, and a project reusing the entry got a new TcGlobals only when langVersion or realsig differed, copying pathMap from the cached instance even then. TypedTreePickle.p_range applies tcGlobals.pathMap to every range it writes and EncodeSignatureData applies it to compileTimeWorkingDir, so the in-memory reference data every project exposes to its consumers was mapped with the --pathmap of whichever project filled the cache first: a project without a map lent mapped, relative file names to its consumers, and a project with a map lost it when a sibling came first.

Seen in Visual Studio on a solution with <PathMap>$(MSBuildThisFileDirectory)=.\</PathMap> in Directory.Build.props: symbols imported from a sibling project carried .\backend\Use cases\Circulars\GraphQL\.\backend\Use cases\Circulars\GraphQL\Types\Circular.fs, and Go To Definition opened the generated signature. #20470 keeps the IDE from passing --pathmap at all; this change makes the cache correct for any host that checks mapped and unmapped projects with one FSharpChecker.

Fix: pathMap takes part in the decision like langVersion and realsig, and the new TcGlobals takes it from the project's own TcConfig — in IncrementalBuild.fs and in TransparentCompiler.fs. The cached framework imports themselves do not depend on the map, so the key is unchanged.

Tests: FSharpChecker/PathMap.fs checks, with one checker for both compilers, a project carrying --pathmap:<root>=.\ first and then an application referencing a library without a map; the library function seen from the application must keep the library's absolute file name. Fails without the fix.

Fixes #20474

Checklist

• Test cases added

• Performance benchmarks added in case of performance changes

• Release notes entry updated:

  Please make sure to add an entry with short succinct description of the change as well as link to this pull request to the respective release notes file, if applicable.

  Release notes files:

  • If anything under src/Compiler has been changed, please make sure to make an entry in docs/release-notes/.FSharp.Compiler.Service/<version>.md, where <version> is usually "highest" one, e.g. 42.8.200
  • If language feature was added (i.e. LanguageFeatures.fsi was changed), please add it to docs/release-notes/.Language/preview.md
  • If a change to FSharp.Core was made, please make sure to edit docs/release-notes/.FSharp.Core/<version>.md where version is "highest" one, e.g. 8.0.200.

  Information about the release notes entries format can be found in the documentation.
  Example:

  • More inlines for Result module. (PR #16106)
  • Correctly handle assembly imports with public key token of 0 length. (Issue #16359, PR #16363)
    *while! (Language suggestion #1038, PR #14238)

  If you believe that release notes are not necessary for this PR, please add NO_RELEASE_NOTES label to the pull request.

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[github-actions]

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✅ Found changes and release notes in following paths:

Change path	Release notes path	Description
`src/Compiler`	docs/release-notes/.FSharp.Compiler.Service/11.0.100.md

[T-Gro]

🤖🕵️ Approved; CI is still running.