Fix asan.test_openjpeg

Since #15083, asan now sets `EXIT_RUNTIME` by default and this test
depends on being able to run a `postRun` handler.

Currently `postRun` handlers are not compatible with `EXIT_RUNTIME`
under node: #15080.

Author: sbc100

tests/test_core.py

@@ -6162,6 +6162,10 @@ def test_poppler(self):
   @needs_make('make')
   @is_slow_test
   def test_openjpeg(self):
+    # Explictly disable EXIT_RUNTIME, since otherwise addOnPostRun does not work.
+    # https://github.com/emscripten-core/emscripten/issues/15080
+    self.set_setting('EXIT_RUNTIME', 0)
+
     def do_test_openjpeg():
       def line_splitter(data):
         out = ''