[native_toolchain_c] Fix MSVC builds when paths contain spaces

[jakobkordez]

Description

Building with MSVC failed with 'C:\Program' is not recognized as an internal or external command whenever a source or include path contained a space —
e.g. the default pub cache under a Windows user name with a space
(C:\Users\First Last\AppData\Local\Pub\Cache\...).

The cause: runProcess ran every command through cmd.exe /c on Windows
(when a working directory was set), and cmd strips the outer quotes once the
command line contains more than two quote characters — so a quoted cl.exe
path plus one quoted argument was enough to mangle the invocation.

Changes:

• runProcess no longer runs through a shell; cl.exe/lib.exe are invoked
  directly. (No caller needs shell features: on Windows programs expand
  wildcards themselves, and the vcvars environment setup uses its own
  Process.run.) As a consequence, cmd.exe %VAR% expansion no longer
  applies to compiler flags/defines — they now reach the tools verbatim.
• The archiver is now passed the object file names derived from sources
  (matching cl.exe /c's naming) instead of *.obj. This keeps object files
  left in the output directory by other builds out of the archive, and keeps
  archive member names short and machine-independent instead of embedding
  the local build path (verified with lib.exe /list).
• The logged command line now quotes the executable and spaced arguments so
  it can be copy-pasted to reproduce an invocation.
• Adds a Windows regression test building a library (dynamic + static) with
  spaces in the source, include, and output paths.
• Bumps to 0.19.3.

Related Issues

Fixes #3321.
Fixes #2848.

PR Checklist

• I’ve reviewed the contributor guide and applied the relevant portions to this PR.
• I've run dart tool/ci.dart --all locally and resolved all issues identified. This ensures the PR is formatted, has no lint errors, and ran all code generators. This applies to the packages part of the toplevel pubspec.yaml workspace.
• All existing and new tests are passing. I added new tests to check the change I am making.
• The PR is actually solving the issue. PRs that don't solve the issue will be closed. Please be respectful of the maintainers' time. If it's not clear what the issue is, feel free to ask questions on the GitHub issue before submitting a PR.
• I have updated CHANGELOG.md for the relevant packages. (Not needed for small changes such as doc typos).
• I have updated the pubspec package version if necessary.

[jakobkordez]

@dcharkes do you mind checking this out?
Thanks

[github-actions]

Package publishing

If you have publishing permissions, you can use the links below to publish the changes after merging this PR.

Package	Version	Status	Publish tag (post-merge)
package:code_assets	1.2.1	already published at pub.dev
package:data_assets	0.20.0	already published at pub.dev
package:ffi	2.2.0	already published at pub.dev
package:hooks	2.0.2	already published at pub.dev
package:hooks_runner	1.5.1-wip	WIP (no publish necessary)
package:jni_flutter	1.0.1	already published at pub.dev
package:native_toolchain_c	0.19.3	ready to publish	native_toolchain_c-v0.19.3
package:record_use	0.6.1-wip	WIP (no publish necessary)
package:swift2objc	0.2.0	already published at pub.dev
package:swiftgen	0.1.3-wip	WIP (no publish necessary)

Documentation at https://github.com/dart-lang/ecosystem/wiki/Publishing-automation.

[github-actions]

PR Health

Breaking changes ✔️

Package	Change	Current Version	New Version	Needed Version	Looking good?
native_toolchain_c	None	0.19.2	0.19.3-wip	0.19.3-wip	✔️

This check can be disabled by tagging the PR with skip-breaking-check.

API leaks ✔️

The following packages contain symbols visible in the public API, but not exported by the library. Export these symbols or remove them from your publicly visible API.

Package	Leaked API symbol	Leaking sources

This check can be disabled by tagging the PR with skip-leaking-check.

Changelog Entry ✔️

Package	Changed Files

Changes to files need to be accounted for in their respective changelogs.

This check can be disabled by tagging the PR with skip-changelog-check.

[dcharkes]

Thanks!

[dcharkes]

Hm, I don't remember why I did this. I remember it was to work around some other bug. But let's try removing it and see if anything breaks.

[jakobkordez]

runInShell was modified in #1759.
Check out the diff https://github.com/dart-lang/native/pull/1759/changes#diff-a9ce5e451f2dda3e3d822fa8660b26845b97441b58e55575af6673bb9e176cbeL59

Also the run_process.dart in the hooks_runner:

runInShell:
          Platform.isWindows &&
          (!includeParentEnvironment || workingDirectory != null),

It seems to be a blend of both?