Add missing tracers for servo #395

Job	Run time
Integrity	19s
linux (--features debugmozjs)	16m 54s
linux	13m 10s
mac (--features debugmozjs)	19m 19s
mac	18m 13s
windows (--features debugmozjs)	17m 15s
windows (--features debugmozjs, aarch64-uwp-windows-msvc)	23m 9s
windows (--features debugmozjs, x86_64-uwp-windows-msvc)	16m 14s
windows	16m 32s
windows (aarch64-uwp-windows-msvc)	19m 10s
windows (x86_64-uwp-windows-msvc)	15m 6s
Result	1s
	2h 55m 22s

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