reduce size by 8 byte on 64 bit
fix possible nullptr derefrence
fix possible null ptr deref
reduce the struct size by 8 byte on x64
reduce the struct size by 8 bytes on 64 bit
reduce the struct size by 8 byte on 64 bit
fix condition

A char array like val[1] would always be valid when checking like
!val. Probably better were to check for ->len, but actually ->val[0]
is fine as the actual zend_string should have been initalized
before.
reduced the struct size by 8 byte on 64 bit
reduce the struct size by 8 byte on 64 bit

this one looks like debug only, but still useful
switch to using mbrlen with VS