swift-4.2.2-RELEASE: IR: fix documentation markup

Use `\brief` instead of `\Brief`.  NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334627 91177308-0d34-0410-b5e6-96231b3b80d8

Swift 4.2.1 Release

IR: fix documentation markup

Use `\brief` instead of `\Brief`.  NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334627 91177308-0d34-0410-b5e6-96231b3b80d8

Swift 4.2 Release

SelectionDAGBuilder, mach-o: Skip trap after noreturn call (for Mach-O)

Add NoTrapAfterNoreturn target option which skips emission of traps
behind noreturn calls even if TrapUnreachable is enabled.

Enable the feature on Mach-O to save code size; Comments suggest it is
not possible to enable it for the other users of TrapUnreachable.

rdar://41530228

DifferentialRevision: https://reviews.llvm.org/D48674

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335877 91177308-0d34-0410-b5e6-96231b3b80d8