Fix JIT crash due to unverified dead code

The JIT compiler assumes that it only gets completely verified code. To
work around potential unverified dead code it uses kAccDontBotherCompile
flag set during runtime verification. However, if a class is verified
during a prior dex2oat the flag is not persisted and JIT happily things
that everything is ok.

The simplest fix is to mark classes with potential unverified dex code
as verify at runtime. We only do this for apps and assume that
everything in the boot image is well formed.

Test: m test-art-host-706-jit-skip-compilation
Bug: 31000839

Change-Id: Ib73de1888581bb7202474cfd7aca70af4cc2cc00