Make wasm-split tests less fragile. NFC (emscripten-core#15150)

tests/other/test_split_main_module.out

@@ -1,3 +1,3 @@
-wrote profile of 240 bytes (allocated 240 bytes)
+wrote profile data
 Hello from main!
 Hello from lib!

tests/other/test_split_module.out

@@ -1,2 +1,2 @@
-wrote profile of 228 bytes (allocated 228 bytes)
+wrote profile data
 Hello! answer: 42

tests/other/test_split_module.post.js

@@ -6,7 +6,8 @@ function saveProfileData() {
     var actualLen = __write_profile(offset, len);
     var profile_data = new Uint8Array(buffer, offset, len);
     nodeFS.writeFileSync('profile.data', profile_data);
-    console.log('wrote profile of', actualLen, 'bytes (allocated', len, 'bytes)');
+    console.log('profile size is', actualLen, 'bytes (allocated', len, 'bytes)');
+    console.log('wrote profile data')
     _free(offset);
   }
 

tests/test_other.py

@@ -10475,7 +10475,10 @@ def test_split_module(self, customLoader):
     self.assertIn('Hello! answer: 42', result)
 
   def test_split_main_module(self):
-    initialTableSize = 17
+    # Set and reasonably large initial table size to avoid test fragility.
+    # The actual number of slots needed is closer to 18 but we don't want
+    # this test to fail every time that changes.
+    initialTableSize = 100
 
     side_src = test_file('other/lib_hello.c')
     post_js = test_file('other/test_split_module.post.js')