Bug 1783138 - Add --enable-jitspew to the WASI build. r=arai

This adds some useful testing functions such as `dis` and `dumpObject`.
It increases the size of the js.wasm file by about 1%.

Differential Revision: https://phabricator.services.mozilla.com/D153717

js/src/devtools/automation/variants/wasi

@@ -1,5 +1,5 @@
 {
-    "configure-args": "--enable-application=js --target=wasm32-unknown-wasi --disable-stdcxx-compat --without-system-zlib --without-intl-api --disable-jit --disable-shared-js --disable-shared-memory --disable-tests --disable-clang-plugin --disable-debug-symbols",
+    "configure-args": "--enable-application=js --target=wasm32-unknown-wasi --disable-stdcxx-compat --without-system-zlib --without-intl-api --disable-jit --disable-shared-js --disable-shared-memory --disable-tests --disable-clang-plugin --disable-debug-symbols --enable-jitspew",
     "optimize": true,
     "debug": false,
     "nspr": false,