markdown: make the oversized-input test robust on loaded debug+ASAN runners

The child reserves 4 GiB and runs under a debug+ASAN build: give the test the
same explicit timeout its perf-test neighbors in this file use, and let the
ASan allocator return null so an allocation failure inside the child surfaces
as a catchable error (the SKIP branch) instead of an abort it cannot catch.

Author: robobun

test/js/bun/md/md-edge-cases.test.ts

@@ -1196,7 +1196,10 @@ describe("inputs of 2^32 bytes or more", () => {
   // every entry point. One subprocess covers all four: a crash must not take
   // down the test runner, and one 4 GiB reservation (virtual only, never
   // written) keeps this cheap. The SKIP branch covers runners that cannot
-  // reserve 4 GiB at all.
+  // reserve 4 GiB; under ASAN the allocator must be allowed to return null
+  // for that to surface as a catchable error rather than an abort. The
+  // explicit timeout is for the debug+ASAN lanes, where a spawned child is
+  // slow under load (same as the linear-time test above).
   test("html, ansi, render and react reject a 2^32-byte input", async () => {
     const script = `
       let big;
@@ -1225,7 +1228,10 @@ describe("inputs of 2^32 bytes or more", () => {
     `;
     await using proc = Bun.spawn({
       cmd: [bunExe(), "-e", script],
-      env: bunEnv,
+      env: {
+        ...bunEnv,
+        ASAN_OPTIONS: [bunEnv.ASAN_OPTIONS, "allocator_may_return_null=1"].filter(Boolean).join(":"),
+      },
       stdout: "pipe",
       stderr: "inherit",
     });
@@ -1236,5 +1242,5 @@ describe("inputs of 2^32 bytes or more", () => {
       JSON.parse(stdout.trim() || '"NO_OUTPUT"'),
     );
     expect(exitCode).toBe(0);
-  });
+  }, 30_000);
 });