Solaris 9 has Perl 5.6.1, which does not support constant declaration
using a hash reference:
$ make check
./tests/TESTrun
Constant name 'HASH(0x2d8f0)' has invalid characters at ./tests/TESTrun
line 24
BEGIN failed--compilation aborted at ./tests/TESTrun line 24.
*** Error code 255
make: Fatal error: Command failed for target `check'
Declare one constant at a time to work around that and get "make check"
to start running tests (18 of which fail, but that's another issue).
#
# Make true and false work as Booleans.
#
-use constant { true => 1, false => 0 };
+use constant true => 1;
+use constant false => 0;
use File::Basename;
use POSIX qw( WEXITSTATUS WIFEXITED);