When tree-ssa was merged, frv-elf stopped building.  cmovh.c for
libgcc was what failed to build.  Here's a minimized testcase:

void f(int a, int b, int c) {
  if (a < b || a > b + 1)
    while (c)
      --c;
}

This crashed when flow for sched2 realized LR, that wasn't live
before, had become live because a direct return (that uses LR) was
inserted in postreload.

Richard Sandiford had already written a patch for what I believe to be
an earlier occurrence of this problem, back when he introduced
conditional returns.  Here's the patch.  I'm tempted to install it as
obvious, but...  Ok?