[liftoff][arm] Run mjsunit liftoff tests on arm

Add the arm architecture to the list of archs that support
Liftoff in mjsunit and so run the Liftoff tests for it.

Bug: v8:6600
Change-Id: I4896f0727f6ccc3343f5d517e100840f76dd901d
Reviewed-on: https://chromium-review.googlesource.com/c/1357040Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57976}

test/mjsunit/mjsunit.status

@@ -897,12 +897,13 @@
 }], # arch != x64 or deopt_fuzzer
 
 ##############################################################################
-# Liftoff is currently only sufficiently implemented on x64, ia32 and arm64.
+# Liftoff is currently only sufficiently implemented on x64, ia32, arm64 and
+# arm.
 # TODO(clemensh): Implement on all other platforms (crbug.com/v8/6600).
-['arch != x64 and arch != ia32 and arch != arm64', {
+['arch != x64 and arch != ia32 and arch != arm64 and arch != arm', {
   'wasm/liftoff': [SKIP],
   'wasm/tier-up-testing-flag': [SKIP],
-}], # arch != x64 and arch != ia32 and arch != arm64
+}], # arch != x64 and arch != ia32 and arch != arm64 and arch != arm
 
 ##############################################################################
 ['variant == slow_path and gc_stress', {