scripted-diff: Following the C++ Standard rules for identifiers with _.

Any identifier starting with two _, or one _ followed by a capital letter is reserved for the compiler and thus must not be used. See: https://stackoverflow.com/a/228797/7130273

-BEGIN VERIFY SCRIPT-
s() { git grep -l "$1" src | xargs sed -i "s/$1/$2/g"; }

s '__pushKV' 'pushKVEnd'
s '_EraseTx' 'EraseTxNoLock'
s '_Other' 'Other'
-END VERIFY SCRIPT-

src/support/allocators/secure.h

@@ -32,9 +32,9 @@ struct secure_allocator : public std::allocator<T> {
     {
     }
     ~secure_allocator() noexcept {}
-    template <typename _Other>
+    template <typename Other>
     struct rebind {
-        typedef secure_allocator<_Other> other;
+        typedef secure_allocator<Other> other;
     };
 
     T* allocate(std::size_t n, const void* hint = nullptr)

src/support/allocators/zeroafterfree.h

@@ -27,9 +27,9 @@ struct zero_after_free_allocator : public std::allocator<T> {
     {
     }
     ~zero_after_free_allocator() noexcept {}
-    template <typename _Other>
+    template <typename Other>
     struct rebind {
-        typedef zero_after_free_allocator<_Other> other;
+        typedef zero_after_free_allocator<Other> other;
     };
 
     void deallocate(T* p, std::size_t n)