Auto merge of #19633 - tigercosmos:vv, r=emilio

pass -vv through mach to cargo

<!-- Please describe your changes on the following line: -->
base on #17237, which is reviewed by emilio and jdm.
just need to rename commit and rebase

---
<!-- 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
- [X] These changes fix #17231 (github issue number if applicable).

<!-- Either: -->
- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because _____

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

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

<!-- 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/19633)
<!-- Reviewable:end -->

python/servo/build_commands.py

@@ -167,15 +167,18 @@ class MachCommands(CommandBase):
     @CommandArgument('--verbose', '-v',
                      action='store_true',
                      help='Print verbose output')
+    @CommandArgument('--very-verbose', '-vv',
+                     action='store_true',
+                     help='Print very verbose output')
     @CommandArgument('params', nargs='...',
                      help="Command-line arguments to be passed through to Cargo")
     @CommandArgument('--with-debug-assertions',
                      default=None,
                      action='store_true',
                      help='Enable debug assertions in release')
     def build(self, target=None, release=False, dev=False, jobs=None,
-              features=None, android=None, verbose=False, debug_mozjs=False, params=None,
-              with_debug_assertions=False):
+              features=None, android=None, verbose=False, very_verbose=False,
+              debug_mozjs=False, params=None, with_debug_assertions=False):
 
         opts = params or []
         opts += ["--manifest-path", self.servo_manifest()]
@@ -223,6 +226,8 @@ def build(self, target=None, release=False, dev=False, jobs=None,
             opts += ["-j", jobs]
         if verbose:
             opts += ["-v"]
+        if very_verbose:
+            opts += ["-vv"]
 
         if android:
             target = self.config["android"]["target"]