Need help diagnosing a z/OS compilation problem

The good news is that z/OS now passes all tests run on blead!  I'll post 
some more details on what this means and future plans tomorrow (my time).

There is one test that is skipped in this blead testing because I didn't 
see how to fix it, and no one stepped forward to help at the time.  I'm 
now thinking it might be fairly easy to get it to work, and maybe since 
we're now so close, someone will look at it.

The test involves trying to compile on the platform.  It is 
dist/ExtUtils-CBuilder/t/02-link.t

The messages below the ===== line are output when the test runs.  The 
ones before the first ok are warnings and appear in other tests that 
pass, so that's not the problem here, though it would be better to not 
have them show up.  But I think the main errors are these two things:

IEW2456E 9207 SYMBOL @@ROND UNRESOLVED.
IEW2456E 9207 SYMBOL CEEROOTD UNRESOLVED

I have no idea where these are coming from, but I bet a z/OS person might.

=========================================
FSUM3212 c99: Command option -x is incorrect for z/OS platform - ignored.
FSUM3228 c99: Input file c++ not found.
CCN0461(W) "EXTC89" is not a valid sub-option for "LANGLVL". Option is 
ignored.
CCN0461(W) "EXTC99" is not a valid sub-option for "LANGLVL". Option is 
ignored.
CCN8101(W) The numeric value "3296" specified in 
"report(treatAsError,3296)" is out of bounds. The option is ignored.
CCN8101(W) The numeric value "4108" specified in 
"report(treatAsError,4108)" is out of bounds. The option is ignored.
dist/ExtUtils-CBuilder/t/00-have-compiler ..................... ok
  IEW2689W 4C40 DEFINITION SIDE FILE IS NOT DEFINED. 

FSUM3065 The LINKEDIT step ended with return code 4.
  IEW2689W 4C40 DEFINITION SIDE FILE IS NOT DEFINED. 

FSUM3065 The LINKEDIT step ended with return code 4.
dist/ExtUtils-CBuilder/t/01-basic ............................. ok
  IEW2689W 4C40 DEFINITION SIDE FILE IS NOT DEFINED. 

FSUM3065 The LINKEDIT step ended with return code 4.
INFORMATIONAL CCN3684 t/linkt.c:1     Exporting function main is not 
allowed.
  IEW2456E 9207 SYMBOL @@ROND UNRESOLVED.  MEMBER COULD NOT BE INCLUDED 
FROM THE
           DESIGNATED CALL LIBRARY. 

  IEW2456E 9207 SYMBOL CEEROOTD UNRESOLVED.  MEMBER COULD NOT BE 
INCLUDED FROM
           THE DESIGNATED CALL LIBRARY. 

FSUM3065 The LINKEDIT step ended with return code 8.
#   Failed test 'no exception from linking'
#   at t/02-link.t line 54.
#          got: 'error building t/linkt from t/linkt.o at 
../../lib/ExtUtils/CBuilder/Base.pm line 320.
# '
#     expected: ''
Use of uninitialized value $exe_file in -e at t/02-link.t line 55.
#   Failed test 'found executable file'
#   at t/02-link.t line 55.
Use of uninitialized value $exe_file in -x at t/02-link.t line 56.
#   Failed test 'executable file appears to be executable'
#   at t/02-link.t line 56.
Use of uninitialized value $cmd in system at t/02-link.t line 94.
#   Failed test 'got expected exit code from executable'
#   at t/02-link.t line 68.
#          got: '255'
#     expected: '11'
# Unexpected exit code '255'
Use of uninitialized value $_ in transliteration (tr///) at t/02-link.t 
line 75.
Use of uninitialized value $_ in unlink at t/02-link.t line 76.
# Looks like you failed 4 tests of 8.
dist/ExtUtils-CBuilder/t/02-link.t .............................. FAILED 
at test 5