[lldb] Make "inline" tests more configurable

Summary:
This patch adds two new arguments to the MakeInlineTest function. The
main motivation is a follow-up patch I'm preparing, but they seem
generally useful.

The first argument allows the user to specify the "build dictionary".
With this argument one can avoid the need to provide a custom Makefile
if all he needs is to override a couple of make variables. This hooks in
neatly into the existing dictionary support for non-inline tests.

The second argument specifies the name of the test. This could be used
to provide better names to the generated test classes, but it's mainly
useful in conjuction with the first argument: now that we can specify a
custom build dictionary, it may sometimes make sense to run the same
test twice with different build configurations. To achieve that, we need
to give the two tests different names, and this argument achieves that.

The usage of the arguments is demonstrated via TestBasicEntryValues.py.

Reviewers: vsk, JDevlieghere

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D80518