<rdar://problem/14496092>

Fixed an issue with reexported symbols on MacOSX by adding support for symbols re-exporting symbols. There is now a new symbol type eSymbolTypeReExported which contains a new name for the re-exported symbol and the new shared library. These symbols are only used when a symbol is re-exported as a symbol under a different name.

Modified the expression parser to be able to deal with finding the re-exported symbols and track down the actual symbol it refers to.

llvm-svn: 193101