Right now when running `expr --top-level -- void foo() {}`, LLDB just prints a cryptic
`error: Couldn't find $__lldb_expr() in the module` error. The reason for that is
that if we don't have a running process, we try to set our execution policy to always use the
IR interpreter (ExecutionPolicyNever) which works even without a process. However
that code didn't consider the special ExecutionPolicyTopLevel which we use for
top-level expressions. By changing the execution policy to ExecutionPolicyNever,
LLDB thinks we're actually trying to interpret a normal expression inside our
`$__lldb_expr` function and then fails when looking for it.
This just adds an exception for top-level expressions to that code and a bunch of tests.
Reviewed By: shafik
Differential Revision: https://reviews.llvm.org/D91723
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
