[lldb][test] Remove symlink for API tests.

Summary: Moves lldbsuite tests to lldb/test/API.

This is a largely mechanical change, moved with the following steps:

```
rm lldb/test/API/testcases
mkdir -p lldb/test/API/{test_runner/test,tools/lldb-{server,vscode}}
mv lldb/packages/Python/lldbsuite/test/test_runner/test lldb/test/API/test_runner
for d in $(find lldb/packages/Python/lldbsuite/test/* -maxdepth 0 -type d | egrep -v "make|plugins|test_runner|tools"); do mv $d lldb/test/API; done
for d in $(find lldb/packages/Python/lldbsuite/test/tools/lldb-vscode -maxdepth 1 -mindepth 1 | grep -v ".py"); do mv $d lldb/test/API/tools/lldb-vscode; done
for d in $(find lldb/packages/Python/lldbsuite/test/tools/lldb-server -maxdepth 1 -mindepth 1 | egrep -v "gdbremote_testcase.py|lldbgdbserverutils.py|socket_packet_pump.py"); do mv $d lldb/test/API/tools/lldb-server; done
```

lldb/packages/Python/lldbsuite/__init__.py and lldb/test/API/lit.cfg.py were also updated with the new directory structure.

Reviewers: labath, JDevlieghere

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71151

lldb/test/API/python_api/value/empty_class/Makefile

@@ -0,0 +1,3 @@
+CXX_SOURCES := main.cpp
+
+include Makefile.rules

lldb/test/API/python_api/value/empty_class/TestValueAPIEmptyClass.py

@@ -0,0 +1,56 @@
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+class ValueAPIEmptyClassTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @add_test_categories(['pyapi'])
+    def test(self):
+        self.build()
+        exe = self.getBuildArtifact("a.out")
+        line = line_number('main.cpp', '// Break at this line')
+
+        # Create a target by the debugger.
+        target = self.dbg.CreateTarget(exe)
+        self.assertTrue(target, VALID_TARGET)
+
+        # Create the breakpoint inside function 'main'.
+        breakpoint = target.BreakpointCreateByLocation('main.cpp', line)
+        self.assertTrue(breakpoint, VALID_BREAKPOINT)
+
+        # Now launch the process, and do not stop at entry point.
+        process = target.LaunchSimple(
+            None, None, self.get_process_working_directory())
+        self.assertTrue(process, PROCESS_IS_VALID)
+
+        # Get Frame #0.
+        self.assertTrue(process.GetState() == lldb.eStateStopped)
+        thread = lldbutil.get_stopped_thread(
+            process, lldb.eStopReasonBreakpoint)
+        self.assertTrue(
+            thread.IsValid(),
+            "There should be a thread stopped due to breakpoint condition")
+        frame0 = thread.GetFrameAtIndex(0)
+
+        # Verify that we can access to a frame variable with an empty class type
+        e = frame0.FindVariable('e')
+        self.assertTrue(e.IsValid(), VALID_VARIABLE)
+        self.DebugSBValue(e)
+        self.assertEqual(e.GetNumChildren(), 0)
+
+        # Verify that we can acces to a frame variable what is a pointer to an
+        # empty class
+        ep = frame0.FindVariable('ep')
+        self.assertTrue(ep.IsValid(), VALID_VARIABLE)
+        self.DebugSBValue(ep)
+
+        # Verify that we can dereference a pointer to an empty class
+        epd = ep.Dereference()
+        self.assertTrue(epd.IsValid(), VALID_VARIABLE)
+        self.DebugSBValue(epd)
+        self.assertEqual(epd.GetNumChildren(), 0)
+

lldb/test/API/python_api/value/empty_class/main.cpp

@@ -0,0 +1,15 @@
+//===-- main.cpp ------------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+class Empty {};
+
+int main (int argc, char const *argv[]) {
+  Empty e;
+  Empty* ep = new Empty;
+  return 0; // Break at this line
+}