Removing unused default switch cases in switches over enums that already account for all enumeration values explicitly.
Removing unused default switch cases in switches over enums that already account for all enumeration values explicitly.

(This time I believe I've checked all the -Wreturn-type warnings from GCC & added the couple of llvm_unreachables necessary to silence them. If I've missed any, I'll happily fix them as soon as I know about them)

git-svn-id: a4a6f32337ebd29ad4763b423022f00f68d1c7b7@148262 91177308-0d34-0410-b5e6-96231b3b80d8

lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx