servo: Merge #19633 - pass -vv through mach to cargo (from tigercosmos:vv); r=emilio

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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).

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- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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Source-Repo: https://github.com/servo/servo
Source-Revision: 7c07f31a55e3d6f156e8fa8360eb804f323a0cb1

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : 80c479fc7627f27e21df34ffd61edf4aed7c6dae

servo/python/servo/build_commands.py

@@ -167,6 +167,9 @@ 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',
@@ -174,8 +177,8 @@ class MachCommands(CommandBase):
                      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,
+              features=None, android=None, verbose=False, very_verbose=False,
-              with_debug_assertions=False):
+              debug_mozjs=False, params=None, with_debug_assertions=False):
 
         opts = params or []
         opts += ["--manifest-path", self.servo_manifest()]
@@ -223,6 +226,8 @@ class MachCommands(CommandBase):
             opts += ["-j", jobs]
         if verbose:
             opts += ["-v"]
+        if very_verbose:
+            opts += ["-vv"]
 
         if android:
             target = self.config["android"]["target"]