Revised fix
5117 [CTFE] Member function call with rather complex this: side effects ignored

This one fixes at least 3 bugs, maybe more:
4915 auto return type escapes function purity

Some other ICE patches:

4529 Segfault(typinf.c) involving typeid(typeof(functionName))
4728 Segfault(toctype.c) by protected/private constructor in an other module
5159 Segfault(interpret.c): calling a static function pointer variable in CTFE
5180 ICE(arrayop.c) in-place array operation on incompatible types

Although this next bug sounds unimportant, it fixes a few important
infrastructure bugs.
5164 Error without line number using "is (T...)"

Since we're not near the end of a release cycle, can we try this one
again? It seems to be a blocker for people using VisualD.
190 Cannot forward reference typedef/alias in default value for
function parameter
It needs to have this patch applied as well:
4753 fail_compilation/fail116.d sends dmd into a loop, exhausting memory