[mips]: Skip mjsunit/harmony/bigint/regressions.

This test creates a BigInt object with size more then 250 MB. On certain
test systems, this large memory consumption will cause the test failing.
Therefore, this test will be skipped for MIPS32 architecture.

TEST=mjsunit/harmony/bigint/regressions
BUG=

Change-Id: I21bf86c3e6058818c6db3ed8970c0f1e3873e0a6
Reviewed-on: https://chromium-review.googlesource.com/962381
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Cr-Commit-Position: refs/heads/master@{#51940}

test/mjsunit/mjsunit.status

@@ -541,6 +541,7 @@
   # Requires too much memory on MIPS.
   'regress/regress-752764': [SKIP],
   'regress/regress-779407': [SKIP],
+  'harmony/bigint/regressions': [SKIP],
 }],  # 'arch == mipsel or arch == mips'
 
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