[mips] Enable mjsunit/regress/wasm/regress-864509 on big-endian

Issues that caused failure of this test have been resolved with commit
https://chromium-review.googlesource.com/c/v8/v8/+/1213183, so it can
be re-enabled.

Change-Id: I441998e5e63fce7a7e718b593c8e58a71841b78e
Reviewed-on: https://chromium-review.googlesource.com/1215168Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Sreten Kovacevic <skovacevic@wavecomp.com>
Cr-Commit-Position: refs/heads/master@{#55754}

test/mjsunit/mjsunit.status

@@ -316,9 +316,6 @@
   'asm/sqlite3/*': [SKIP],
   # TODO(mips-team): Fix Wasm for big-endian.
   'wasm/*': [SKIP],
-  # TODO(mips-team): Fix SEGV on regress-864509.js on big endian
-  # (https://crbug.com/v8/7953).
-  'regress/wasm/regress-864509': [SKIP],
 }],  # 'byteorder == big'
 
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