Auto merge of #16210 - jdm:updatejs, r=Wafflespeanut

Update rust-mozjs to master.

- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #16152
- [X] There are tests for these changes

<!-- 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/16210)
<!-- Reviewable:end -->

Cargo.lock

@@ -1307,7 +1307,7 @@ dependencies = [
 [[package]]
 name = "js"
 version = "0.1.4"
-source = "git+https://github.com/servo/rust-mozjs#101c6b6b58e0b7c5ed1ef2b6b676a7497f90df2f"
+source = "git+https://github.com/servo/rust-mozjs#7f380abcbe02604cca5f28ff4175dff2a4f5555e"
 dependencies = [
  "cmake 0.1.22 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",