At the moment nearly every test calls something similar to
`self.dbg.CreateTarget(self.getBuildArtifact("a.out"))` and them sometimes
checks if the created target is actually valid with something like
`self.assertTrue(target.IsValid(), "some useless text")`.
Beside being really verbose the error messages generated by this pattern are
always just indicating that the target failed to be created but now why.
This patch introduces a helper function `createTestTarget` to our Test class
that creates the target with the much more verbose `CreateTarget` overload that
gives us back an SBError (with a fancy error). If the target couldn't be created
the function prints out the SBError that LLDB returned and asserts for us. It
also defaults to the "a.out" build artifact path that nearly all tests are using
to avoid to hardcode "a.out" in every test.
I converted a bunch of tests to the new function but I'll do the rest of the
test suite as follow ups.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D102771
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
