Remove GG_VA_COPY in favor of va_copy

third_party/cld/base/port.h

Index: third_party/cld/base/port.h
diff --git a/third_party/cld/base/port.h b/third_party/cld/base/port.h
index 3f363ed79e61f63a4216e1c4cae1d97f9a97fda0..ddd7510b840f711d9ed4b1e67f30d5859c8ab7f7 100644
--- a/third_party/cld/base/port.h
+++ b/third_party/cld/base/port.h
@@ -32,18 +32,6 @@
 #define GG_UINT32_C(x)  (x ## U)
 #define GG_UINT64_C(x)  GG_ULONGLONG(x)
 
-// It's possible for functions that use a va_list, such as StringPrintf, to
-// invalidate the data in it upon use.  The fix is to make a copy of the
-// structure before using it and use that copy instead.  va_copy is provided
-// for this purpose.  MSVC does not provide va_copy, so define an
-// implementation here.  It is not guaranteed that assignment is a copy, so the
-// StringUtil.VariableArgsFunc unit test tests this capability.
-#if defined(COMPILER_GCC)
-#define GG_VA_COPY(a, b) (va_copy(a, b))
-#elif defined(COMPILER_MSVC)
-#define GG_VA_COPY(a, b) (a = b)
-#endif
-
 // Define an OS-neutral wrapper for shared library entry points
 #if defined(OS_WIN)
 #define API_CALL __stdcall