Fixed an error where the thread index was being returned as zero in "uint32_t...

Fixed an error where the thread index was being returned as zero in "uint32_t SBBreakpoint::GetThreadIndex() const" even when it isn't specified. It should be UINT32_MAX to indicate there is no thread index set for the breakpoint (the breakpoint isn't thread specific). Also fixed the ThreadSpec.cpp to use UINT32_MAX instead of -1. Fixed the logging Printf statement in "uint32_t SBBreakpoint::GetThreadIndex() const" to not print the address of the "index" function from <string.h>!

llvm-svn: 121896