Squashed 'src/leveldb/' changes from 22f1e4a02f..e2f10b4e47

e2f10b4e47 Merge bitcoin-core/leveldb-subtree#34: win32: fix -Wmissing-field-initializers warnings
12c52b392d win32: fix -Wmissing-field-initializers warnings

git-subtree-dir: src/leveldb
git-subtree-split: e2f10b4e47bc950a81bc96d1c6db3a8048216642

Author: fanquake

util/env_windows.cc

@@ -194,7 +194,7 @@ class WindowsRandomAccessFile : public RandomAccessFile {
   Status Read(uint64_t offset, size_t n, Slice* result,
               char* scratch) const override {
     DWORD bytes_read = 0;
-    OVERLAPPED overlapped = {0};
+    OVERLAPPED overlapped = {};
 
     overlapped.OffsetHigh = static_cast<DWORD>(offset >> 32);
     overlapped.Offset = static_cast<DWORD>(offset);