Making a manual mode of operation for measurements, where you can manually call start() and stop() instead of using the function-call syntax
This is especially useful to take measurements that span multiple test steps, or where you need to have different operations fall under the same measurement

An example of use is in the formatters perf test case

llvm-svn: 177597

llvm-svn: 177587

- TestCase.m_thread is now filled in with the first thread that has a valid
  stop reason. This eliminates the need for the SelectMyThread() functions.
- The first thread that stops for a reason is also set as the selected thread
  in the process in case any command line commands are run.
- Changed launch over to take a SBLaunchInfo parameter so that the launch
  function doesn't keep getting new arguments as they are needed.
- TestCase::Setup() and TestCase::Launch(SBLaunchInfo) now return bool to 
  indicate success of setup and launch.
- ActionWanted::Next(SBThread) was renamed to ActionWanted::StepOver(SBThread)
- ActionWanted::Finish(SBThread) was renamed to ActionWanted::StepOut(SBThread)

llvm-svn: 177376

- don't use preprocessor macros
- use switch statements
- don't put anything in the lldb namespace, use "lldb_perf" namespace.
- Pass the action struct into each TestStep() for each step fill in
- Modify the ActionWanted class to have accessors to make the continue, next, finish, kill instead of using preproc macros

llvm-svn: 177332

A test case for the performance of some LLDB formatters
Changes and improvements to the testing infrastructure itself

llvm-svn: 177100