Right now clang_Cursor_getMangling will attempt to mangle any
declaration, even if the declaration isn't mangled (extern C). This
results in a partially mangled name which isn't useful for much. This
patch makes clang_Cursor_getMangling return an empty string if the
declaration isn't mangled.
Patch by Michael Wu <mwu@mozilla.com>.
llvm-svn: 253909
Ehsan Akhgari