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

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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)",

components/script/script_runtime.rs

@@ -126,7 +126,7 @@ unsafe extern "C" fn enqueue_job(cx: *mut JSContext,
 #[allow(unsafe_code)]
 pub unsafe fn new_rt_and_cx() -> Runtime {
     LiveDOMReferences::initialize();
-    let runtime = Runtime::new();
+    let runtime = Runtime::new().unwrap();
 
     JS_AddExtraGCRootsTracer(runtime.rt(), Some(trace_rust_roots), ptr::null_mut());
     JS_AddExtraGCRootsTracer(runtime.rt(), Some(trace_refcounted_objects), ptr::null_mut());