Fix test/slow/program_functions/ini_get_all_second_third.php.expectf

Summary: D1590095 added a new option, but its latest test run was based before
D1591831.

Reviewed By: @markw65

Differential Revision: D1605691
Hardcode array_map typing into typechecker - output typing

Summary: The part where I correctly annotate output type of array_map, split from D1566676 where input parameters are typed, and output is left just as "array". See comment in .hhi file for explanation.

Reviewed By: @elgenie

Differential Revision: D1591816
Stop punting on '' === $s

Summary: Codegen was expecting simplifier to have canonicalized constants to the
right, but simplifier didn't do so in the specific case of Same on
strings. Thanks to vasm, it makes no difference to codegen whether
constants are canonicalized right, so just remove the check from
codegen.

Found this by looking for InterpOne while running Wordpress. This takes
it from 0.3-0.5% of bytecodes interp-oned on most endpoints down to a
consistent 0.1%.

Reviewed By: @ottoni

Differential Revision: D1603546