[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/section/TestSectionAPI.py

@@ -0,0 +1,42 @@
+"""
+Test SBSection APIs.
+"""
+
+
+
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class SectionAPITestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @add_test_categories(['pyapi'])
+    def test_get_target_byte_size(self):
+        d = {'EXE': 'b.out'}
+        self.build(dictionary=d)
+        self.setTearDownCleanup(dictionary=d)
+        exe = self.getBuildArtifact('b.out')
+        target = self.dbg.CreateTarget(exe)
+        self.assertTrue(target, VALID_TARGET)
+
+        # find the .data section of the main module
+        mod = target.GetModuleAtIndex(0)
+        data_section = None
+        for s in mod.sections:
+            sect_type = s.GetSectionType()
+            if sect_type == lldb.eSectionTypeData:
+                data_section = s
+                break
+            elif sect_type == lldb.eSectionTypeContainer:
+                for i in range(s.GetNumSubSections()):
+                    ss = s.GetSubSectionAtIndex(i)
+                    sect_type = ss.GetSectionType()
+                    if sect_type == lldb.eSectionTypeData:
+                        data_section = ss
+                        break
+
+        self.assertIsNotNone(data_section)
+        self.assertEqual(data_section.target_byte_size, 1)