[cfi] Support explicit sections for functions in cfi-icall.

Allow explicit section for indirectly called functions in cfi-icall.
Jumptables for functions in the same type class must be contiguous, so they
always go to the default text section.

Fixes PR25079.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266486 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed