message: Remove some now-unnecessary code in dotest.py.
  This code comes from the simplification to dotest.py upstream
  that changed "compilers" to "compiler" and did some refactoring.
  This has the potential to be fragile, so we'll have to watch our bots.
diff: @@ -1318,32 +1318,6 @@ def run_suite():
  tbl = str.maketrans(' ', '-')
  configPostfix = configString.translate(tbl)
  - if configuration.compilers is None and "compilers" in config:
  - configuration.compilers = config["compilers"]
  -
  - #
  - # Add some intervention here to sanity check that the compilers requested are sane.
  - # If found not to be an executable program, the invalid one is dropped
  - # from the list.
  - for i in range(len(configuration.compilers)):
  - c = configuration.compilers[i]
  - if which(c):
  - continue
  - else:
  - if sys.platform.startswith("darwin"):
  - pipe = subprocess.Popen(
  - ['xcrun', '-find', c], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
  - cmd_output = pipe.stdout.read()
  - if cmd_output:
  - if "not found" in cmd_output:
  - print("dropping %s from the compilers used" % c)
  - configuration.compilers.remove(i)
  - else:
  - configuration.compilers[i] = cmd_output.split('\n')[0]
  - print(
  - "'xcrun -find %s' returning %s" %
  - (c, configuration.compilers[i]))
  -
  # Output the configuration.
  if not configuration.parsable:
  sys.stderr.write("\nConfiguration: " + configString + "\n")
  