[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/functionalities/data-formatter/data-formatter-python-synth/main.cpp

@@ -0,0 +1,72 @@
+struct foo
+{
+    int a;
+    int b;
+    int c;
+    int d;
+    int e;
+    int f;
+    int g;
+    int h;
+    int i;
+    int j;
+    int k;
+    int l;
+    int m;
+    int n;
+    int o;
+    int p;
+    int q;
+    int r;
+    
+    foo(int X) :
+    a(X),
+    b(X+1),
+    c(X+3),
+    d(X+5),
+    e(X+7),
+    f(X+9),
+    g(X+11),
+    h(X+13),
+    i(X+15),
+    j(X+17),
+    k(X+19),
+    l(X+21),
+    m(X+23),
+    n(X+25),
+    o(X+27),
+    p(X+29),
+    q(X+31),
+    r(X+33) {}
+};
+
+struct wrapint
+{
+    int x;
+    wrapint(int X) : x(X) {}
+};
+
+struct wrapfoo
+{
+    foo *ptr;
+};
+
+int main()
+{
+    foo f00_1(1);
+    foo *f00_ptr = new foo(12);
+    wrapfoo wrapper{f00_ptr};
+
+    f00_1.a++; // Set break point at this line.
+    
+    wrapint test_cast('A' +
+               256*'B' +
+               256*256*'C'+
+               256*256*256*'D');
+    // Set cast break point at this line.
+    test_cast.x = 'Q' +
+	               256*'X' +
+	               256*256*'T'+
+	               256*256*256*'F';
+    return 0;     // Set second cast break point at this line.
+}