shrink the number of 64-bit build warnings

_From [bruen...@google.com](https://code.google.com/u/109494838902877177630/) on April 10, 2014 12:30:01_

With VS2013 the number of warnings crosses a threshold and we get:

WARNING: maximum warning/error limit hit for debug-internal-64!
Manually verify whether it succeeded.

```
134 Warning(s)^M
0 Error(s)^M
```

In the build log, some samples:
ntdll_imports.obj : warning LNK4197: export 'KiUserApcDispatcher' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]

LINK : warning LNK4075: ignoring '/INCREMENTAL' due to '/OPT:REF' specification [D:\derek\dr\build_suite\

The xml has most warnings from issue #938 :
ntdll_imports.obj : warning LNK4197: export 'NtCancelIoFile' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]
ntdll_imports.obj : warning LNK4197: export 'NtCreateProfile' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]
ntdll_imports.obj : warning LNK4197: export 'NtSetIntervalProfile' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]
ntdll_imports.obj : warning LNK4197: export 'NtQueryIntervalProfile' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]
ntdll_imports.obj : warning LNK4197: export 'NtStartProfile' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]
ntdll_imports.obj : warning LNK4197: export 'NtStopProfile' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]
ntdll_imports.obj : warning LNK4197: export 'NtCreateProcess' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]
ntdll_imports.obj : warning LNK4197: export 'NtTerminateProcess' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]
ntdll_imports.obj : warning LNK4197: export 'NtCreateDirectoryObject' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]
ntdll_imports.obj : warning LNK4197: export 'NtOpenDirectoryObject' specified multiple times; using first specification [D:\derek\dr\build_suite\build_debug-internal-64\core\ntimp_tgt.vcxproj]
The maximum number of reported warnings or errors has been reached!!!

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=1422_