[CMake][runtimes] Use target specific name for all runtimes targets

We need to use target specific name for all runtimes targets. Target
specific name means the name of target in the LLVM build is different
from the name in runtimes build (in LLVM build, it's suffixed by the
target itself). Previously we have only used target specific names for
check targets collected through SUB_CHECK_TARGETS, but that's not
sufficient, we need to use target specific names for all targets we're
exposing in LLVM build.

Fixes PR34335.

Differential Revision: https://reviews.llvm.org/D37245

llvm-svn: 312405