Remove "%zu" format specifier for MSVC.

[zturner]

Lgtm. Just as an fyi, 2015 supports %z, so once we raise the minimum
requirement we won't have this problem anymore

[chaoren]

I wonder if it'll be worth the effort to convert everything to use C++
streams instead.

lldb/trunk/source/Symbol/ClangASTType.cpp

switch (parent_type_class)
             {
                 const clang::VectorType *array = llvm::cast<clang::VectorType>(parent_qual_type.getTypePtr());
                 if (array)
                 {
                     ClangASTType element_type (m_ast, array->getElementType());
                     if (element_type.GetCompleteType())
                     {
                         char element_name[64];
-                        ::snprintf (element_name, sizeof (element_name), "[%zu]", idx);
+                        ::snprintf(element_name, sizeof(element_name), "[%" PRIu64 "]", static_cast<uint64_t>(idx));
                         child_name.assign(element_name);
                         child_byte_size = element_type.GetByteSize(exe_ctx ? exe_ctx->GetBestExecutionContextScope() : NULL);
                         child_byte_offset = (int32_t)idx * (int32_t)child_byte_size;
                         return element_type;
                     }
                 }
             }
             break;
             
         case clang::Type::ConstantArray:
         case clang::Type::IncompleteArray:
             if (ignore_array_bounds || idx_is_valid)
             {
                 const clang::ArrayType *array = GetQualType()->getAsArrayTypeUnsafe();
                 if (array)
                 {
                     ClangASTType element_type (m_ast, array->getElementType());
                     if (element_type.GetCompleteType())
                     {
                         char element_name[64];
-                        ::snprintf (element_name, sizeof (element_name), "[%zu]", idx);
+                        ::snprintf(element_name, sizeof(element_name), "[%" PRIu64 "]", static_cast<uint64_t>(idx));
                         child_name.assign(element_name);
                         child_byte_size = element_type.GetByteSize(exe_ctx ? exe_ctx->GetBestExecutionContextScope() : NULL);
                         child_byte_offset = (int32_t)idx * (int32_t)child_byte_size;
                         return element_type;
                     }
                 }
             }
             break;