Auto merge of #12605 - metajack:win-app-fixes, r=larsbergstrom

Fix font metrics and switch to windows subsystem

<!-- Please describe your changes on the following line: -->

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors

<!-- Either: -->
- [ ] These changes do not require tests because they must be manually tested

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

Currently fonts are using incorrect metrics and the app uses the console
subsystem. This patch adds aliases so that font metrics are found and
instructs the linker to use the windows subsystem.

NOTE: This is not yet ready to merge. The RUSTFLAGS isn't getting set right.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/12605)
<!-- Reviewable:end -->

1 files changed, 3 insertions, 0 deletions

diff --git a/python/servo/build_commands.py b/python/servo/build_commands.py
index f344b050f4e..df727e2776f 100644
--- a/python/servo/build_commands.py
+++ b/python/servo/build_commands.py
@@ -236,6 +236,9 @@ class MachCommands(CommandBase):
 
         cargo_binary = "cargo" + BIN_SUFFIX
 
+        if sys.platform == "win32" or sys.platform == "msys":
+            env["RUSTFLAGS"] = "-C link-args=-Wl,--subsystem,windows"
+
         status = call(
             [cargo_binary, "build"] + opts,
             env=env, cwd=self.servo_crate(), verbose=verbose)