Fix a problem with the const_variables test case (another lldb bug remains)
- make the test case step past the location where 'index' is initialized, otherwise its value cannot be printed (verified gcc 4.6/4.7 and recent clang)
- "Couldn't materialize struct" error from LLDB still prevents this test case from passing



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@175653 91177308-0d34-0410-b5e6-96231b3b80d8