Added the ability to read the dSYM plist file with source remappings even when...

Added the ability to read the dSYM plist file with source remappings even when DebugSymbols isn't used to find the dSYM. We now parse the plist as XML in the MacOSX symbol vendor.

Added the ability to get a section load address given a target which is needed for a previous checking which saves crashlogs.

llvm-svn: 159298