Add -Wshorten-64-to-32 flag to mac builds.

src/gdb-jit.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/base/bits.h"
 #include "src/base/platform/platform.h"
 #include "src/bootstrapper.h"
 #include "src/compiler.h"
@@ skipping 337 matching lines @@
   Type type_;
   uintptr_t align_;
   uint16_t index_;
 };
 #endif  // defined(__ELF)
 
 
 #if defined(__MACH_O)
 class MachOTextSection : public MachOSection {
  public:
-  MachOTextSection(uintptr_t align,
+  MachOTextSection(uint32_t align,
                    uintptr_t addr,
                    uintptr_t size)
       : MachOSection("__text",
                      "__TEXT",
                      align,
                      MachOSection::S_REGULAR |
                          MachOSection::S_ATTR_SOME_INSTRUCTIONS |
                          MachOSection::S_ATTR_PURE_INSTRUCTIONS),
         addr_(addr),
         size_(size) { }
@@ skipping 212 matching lines @@
   }
 
 
   void WriteSections(Writer* w,
                      Writer::Slot<MachOSegmentCommand> cmd,
                      Writer::Slot<MachOHeader> header,
                      uintptr_t load_command_start) {
     Writer::Slot<MachOSection::Header> headers =
         w->CreateSlotsHere<MachOSection::Header>(sections_.length());
     cmd->fileoff = w->position();
-    header->sizeofcmds = w->position() - load_command_start;
+    header->sizeofcmds = static_cast<uint32_t>(w->position() -
+        load_command_start);
     for (int section = 0; section < sections_.length(); ++section) {
       sections_[section]->PopulateHeader(headers.at(section));
       sections_[section]->WriteBody(headers.at(section), w);
     }
     cmd->filesize = w->position() - (uintptr_t)cmd->fileoff;
   }
 
   Zone* zone_;
   ZoneList<MachOSection*> sections_;
 };
@@ skipping 1558 matching lines @@
       LineInfo* line_info = reinterpret_cast<LineInfo*>(event->user_data);
       PutLineInfo(reinterpret_cast<Address>(event->code_start), line_info);
       break;
     }
   }
 }
 #endif
 }  // namespace GDBJITInterface
 }  // namespace internal
 }  // namespace v8