Bug 1669196 - Guard a test on word width. r=jseward

A test introduced in bug 1669003 should only be run on 32-bit systems
for now because (a) that's what it's intended for and (b) it will fail
on aarch64 due to bug 1666747 (bad unaligned writes at the end of
memory):

On 32-bit ARM, the test case performs aligned writes and thus tests
what it's supposed to test.  On 64-bit ARM, the write will be
unaligned and hence fail due to the latter bug.

Differential Revision: https://phabricator.services.mozilla.com/D92544

js/src/jit-test/tests/wasm/memory-partial-oob-store.js

@@ -6,6 +6,7 @@
 // when the bug is fixed in the code generator they must remain excluded here.
 var conf = getBuildConfiguration();
 var excluded = conf.arm64 || conf["arm64-simulator"] || conf.arm || conf["arm-simulator"];
+var thirtytwobit = conf["pointer-byte-size"] == 4;
 
 const RuntimeError = WebAssembly.RuntimeError;
 
@@ -123,4 +124,6 @@ for (let align of [0,1,2,4]) {
 // presumed-aligned 32-bit stores.  This tests that we don't store the low
 // word before the high word if the low word is in-bounds but the high word
 // is not.
-testStoreOOB('i64', '', 0x10000 - 4, 0, 0, '0x0123456789abcdef');
+if (thirtytwobit) {
+    testStoreOOB('i64', '', 0x10000 - 4, 0, 0, '0x0123456789abcdef');
+}