Failing test tcl 8.5.2 on Interix - confused

Hello all,
Some test fails in a x86_64 Interix 6.0 compile of tcl 8.5.2 release.

all.tcl: Total 24242  Passed 23170  Skipped 1055  Failed 17

Some of the test fails due to missing encodings.

While looking through the failed test there are some things I
don't understand:

--------------- get.test -------------------

test get-1.8 {Tcl_GetInt procedure} {testgetint longIs64bit} {
    list [catch {testgetint 18446744073709551614} msg] $msg
} {0 -2}
test get-1.9 {Tcl_GetInt procedure} {testgetint longIs64bit} {
    list [catch {testgetint +18446744073709551614} msg] $msg
} {0 -2}

-------------- test output ------------------

==== get-1.8 Tcl_GetInt procedure FAILED
==== Contents of test case:

    list [catch {testgetint 18446744073709551614} msg] $msg

---- Result was:
0 4294967294
---- Result should have been (exact matching):
0 -2