That confuses e.g. machine basic block placement, which then doesn't
realize that control can fall through a block that ends with a conditional
tail call. Instead, isBranch=1 should be set.
Also, mark EFLAGS as used by these instructions.
llvm-svn: 281281
r280832 added 32-bit support for emitting conditional tail-calls, but
dropped imp-used parameter registers. This went unnoticed until
r281113, which added 64-bit support, as this is only exposed with
parameter passing via registers.
Don't drop the imp-used parameters.
llvm-svn: 281223
Hans Wennborg