Remove test_emcc_4. NFC (#26440)

This is a rather sprawling and unfocused test that has a huge loop
inside.

This single test take over 30 seconds to run.

It seems to test for a lot of different things, including stuff from the
old compile-to-JS days. I'm pretty sure all this stuff is covered in a
more logical fashion elsewhere.

It also has a very useless name.

Author: sbc100

test/hello_world_loop.c

@@ -583,90 +583,6 @@ def test_emcc_3(self, compiler, suffix):
       os.chdir(last)
       delete_file(path)
 
-  @is_slow_test
-  @with_both_compilers
-  def test_emcc_4(self, compiler):
-    # Optimization: emcc src.cpp -o something.js [-Ox]. -O0 is the same as not specifying any optimization setting
-    # link_param are used after compiling first
-    for params, opt_level, link_params, closure, has_malloc in [
-      (['-o', 'something.js'],                          0, None, 0, 1),
-      (['-o', 'something.js', '-O0', '-g'],             0, None, 0, 0),
-      (['-o', 'something.js', '-O1'],                   1, None, 0, 0),
-      (['-o', 'something.js', '-O1', '-g'],             1, None, 0, 0), # no closure since debug
-      (['-o', 'something.js', '-O2'],                   2, None, 0, 1),
-      (['-o', 'something.js', '-O2', '-g'],             2, None, 0, 0),
-      (['-o', 'something.js', '-Os'],                   2, None, 0, 1),
-      (['-o', 'something.js', '-O3'],                   3, None, 0, 1),
-      # and, test compiling first
-      (['-c', '-o', 'something.o'],        0, [],      0, 0),
-      (['-c', '-o', 'something.o', '-O0'], 0, [],      0, 0),
-      (['-c', '-o', 'something.o', '-O1'], 1, ['-O1'], 0, 0),
-      (['-c', '-o', 'something.o', '-O2'], 2, ['-O2'], 0, 0),
-      (['-c', '-o', 'something.o', '-O3'], 3, ['-O3'], 0, 0),
-      (['-O1', '-c', '-o', 'something.o'], 1, [],      0, 0),
-      # non-wasm
-      (['-sWASM=0', '-o', 'something.js'],                          0, None, 0, 1),
-      (['-sWASM=0', '-o', 'something.js', '-O0', '-g'],             0, None, 0, 0),
-      (['-sWASM=0', '-o', 'something.js', '-O1'],                   1, None, 0, 0),
-      (['-sWASM=0', '-o', 'something.js', '-O1', '-g'],             1, None, 0, 0), # no closure since debug
-      (['-sWASM=0', '-o', 'something.js', '-O2'],                   2, None, 0, 1),
-      (['-sWASM=0', '-o', 'something.js', '-O2', '-g'],             2, None, 0, 0),
-      (['-sWASM=0', '-o', 'something.js', '-Os'],                   2, None, 0, 1),
-      (['-sWASM=0', '-o', 'something.js', '-O3'],                   3, None, 0, 1),
-      # and, test compiling to bitcode first
-      (['-flto', '-c', '-o', 'something.o'],        0, [],      0, 0),
-      (['-flto', '-c', '-o', 'something.o', '-O0'], 0, [],      0, 0),
-      (['-flto', '-c', '-o', 'something.o', '-O1'], 1, ['-O1'], 0, 0),
-      (['-flto', '-c', '-o', 'something.o', '-O2'], 2, ['-O2'], 0, 0),
-      (['-flto', '-c', '-o', 'something.o', '-O3'], 3, ['-O3'], 0, 0),
-      (['-flto', '-O1', '-c', '-o', 'something.o'], 1, [],      0, 0),
-    ]:
-      print(params, opt_level, link_params, closure, has_malloc)
-      self.clear()
-      keep_debug = '-g' in params
-      if has_malloc:
-        filename = test_file('hello_world_loop_malloc.c')
-      else:
-        filename = test_file('hello_world_loop.c')
-      args = [compiler, filename] + params
-      print('..', args)
-      output = self.run_process(args, stdout=PIPE, stderr=PIPE)
-      assert len(output.stdout) == 0, output.stdout
-      if link_params is not None:
-        self.assertExists('something.o', output.stderr)
-        obj_args = [compiler, 'something.o', '-o', 'something.js'] + link_params
-        print('....', obj_args)
-        output = self.run_process(obj_args, stdout=PIPE, stderr=PIPE)
-      self.assertExists('something.js', output.stderr)
-      self.assertContained('Hello, world!', self.run_js('something.js'))
-
-      # Verify optimization level etc. in the generated code
-      # XXX these are quite sensitive, and will need updating when code generation changes
-      generated = read_file('something.js')
-      main = self.get_func(generated, '_main') if 'function _main' in generated else generated
-      assert 'new Uint16Array' in generated and 'new Uint32Array' in generated, 'typed arrays 2 should be used by default'
-      assert 'SAFE_HEAP_LOAD' not in generated, 'safe heap should not be used by default'
-      assert 'SAFE_HEAP_STORE' not in generated, 'safe heap should not be used by default'
-      assert ': while(' not in main, 'when relooping we also js-optimize, so there should be no labelled whiles'
-      if closure:
-        if opt_level == 0:
-          assert '._main =' in generated, 'closure compiler should have been run'
-        elif opt_level >= 1:
-          assert '._main=' in generated, 'closure compiler should have been run (and output should be minified)'
-      else:
-        # closure has not been run, we can do some additional checks. TODO: figure out how to do these even with closure
-        assert '._main = ' not in generated, 'closure compiler should not have been run'
-        if keep_debug:
-          self.assertContainedIf("assert(typeof Module['STACK_SIZE'] == 'undefined'", generated, opt_level == 0)
-        if 'WASM=0' in params:
-          looks_unminified = ' = {}' in generated and ' = []' in generated
-          looks_minified = '={}' in generated and '=[]' and ';var' in generated
-          assert not (looks_minified and looks_unminified)
-          if opt_level == 0 or '-g' in params:
-            assert looks_unminified
-          elif opt_level >= 2:
-            assert looks_minified
-
   def test_multiple_sources(self):
     # Compiling two sources at a time should work.
     cmd = [EMCC, '-c', test_file('twopart_main.cpp'), test_file('twopart_side.c')]