Fix #206: Null coalescing operator on Vector make search failed

This happens because php_ds_vector_read_dimension makes a REF from the value
when type is not BP_VAR_R. So when the type i

Fix #206: Null coalescing operator on Vector make search failed

This happens because php_ds_vector_read_dimension makes a REF from the value
when type is not BP_VAR_R. So when the type is BP_VAR_IS then we see the first
element becomes a reference. You can see this when doing var_dump.

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review object management

First steps to PHP 8 support

Fix memory leaks, smarter reallocations

Reduce gc_count on deque when head is at 0

Replace allocation macros with safer functions

Fix null coalesce access

Refactoring of php subdirectory prefixes

Add all gc handlers

Fix return dtor macro

Fix many memory leaks

Fix object release memory leaks #30

Improved deque reallocation

Stack refactor

Refactor queue

Object renames, priority queue updates

Initial map renaming

Rebased

Significant include refactor, htable renaming

Deque renaming, prefix fixes

Significant rename to split ds from php