[wasm]: Re-enable Wasm related unit tests on Big endian

The Wasm got big-endian support with d3f3f6c818. The
tests are now passing.

BUG=

Review-Url: https://codereview.chromium.org/2359143002
Cr-Commit-Position: refs/heads/master@{#39635}

test/unittests/unittests.status

@@ -3,15 +3,6 @@
 # found in the LICENSE file.
 
 [
-['byteorder == big', {
-  # TODO(mips-team): Fix Wasm for big-endian.
-  'WasmModuleVerifyTest*': [SKIP],
-  'WasmFunctionVerifyTest*': [SKIP],
-  'WasmDecoderTest.TableSwitch*': [SKIP],
-  'WasmDecoderTest.AllLoadMemCombinations': [SKIP],
-  'AstDecoderTest.AllLoadMemCombinations': [SKIP],
-  'AstDecoderTest.AllStoreMemCombinations': [SKIP],
-}],  # 'byteorder == big'
 ['arch == x87', {
   'Ieee754.Expm1': [SKIP],
   'Ieee754.Cos': [SKIP],