inferior program for the lldb debugger to operate on.  The fixed lldb executable
corresponds to r142902.

Plus some minor modifications to the test benchmark to conform to way bench.py
is meant to be invoked.

llvm-svn: 143075

Add benchmarks for expression evaluations (TestExpressionCmd.py) and disassembly (TestDoAttachThenDisassembly.py).

An example:
[17:45:55] johnny:/Volumes/data/lldb/svn/trunk/test $ ./bench.py 2>&1 | grep -P '^lldb.*benchmark:'
lldb startup delay (create fresh target) benchmark: Avg: 0.104274 (Laps: 30, Total Elapsed Time: 3.128214)
lldb startup delay (set first breakpoint) benchmark: Avg: 0.102216 (Laps: 30, Total Elapsed Time: 3.066470)
lldb frame variable benchmark: Avg: 1.649162 (Laps: 20, Total Elapsed Time: 32.983245)
lldb stepping benchmark: Avg: 0.104409 (Laps: 50, Total Elapsed Time: 5.220461)
lldb expr cmd benchmark: Avg: 0.206774 (Laps: 25, Total Elapsed Time: 5.169350)
lldb disassembly benchmark: Avg: 0.089086 (Laps: 10, Total Elapsed Time: 0.890859)

llvm-svn: 142708