Generate LC_FUNCTION_STARTS load command.

This load command generates data in the LINKEDIT section which
is a list of ULEB128 delta's to all of the functions in the __text section.

It is then 0 terminated and pointer aligned to pad.

ld64 exposes the -function-starts and no-function-starts cmdline options
to override behaviour from the defaults based on file types.

rdar://problem/24472630

llvm-svn: 260188
diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFile.h b/lld/lib/ReaderWriter/MachO/MachONormalizedFile.h
index b561ae8..5328312 100644
--- a/lld/lib/ReaderWriter/MachO/MachONormalizedFile.h
+++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFile.h
@@ -263,6 +263,7 @@
   std::vector<BindLocation>   weakBindingInfo;
   std::vector<BindLocation>   lazyBindingInfo;
   std::vector<Export>         exportInfo;
+  std::vector<uint8_t>        functionStarts;
   std::vector<DataInCode>     dataInCode;
 
   // TODO: