Fix compilation under Perl 6.c

This fixes most of the test failures under a modern rakudobrew

$ perl6 --version
This is Rakudo version 2015.12-221-g85d20f3 built on MoarVM version 2015.12-29-g8079ca5
implementing Perl 6.c.

The following tests however still fail

$ prove -e perl6
t/01-connect.t ............ ok   
t/02-connection.t ......... ok   
t/02-hashes.t ............. ok     
t/02-keys.t ............... 1/21 
# Failed test at t/02-keys.t line 43
# expected: -1
#      got: -2

# Failed test at t/02-keys.t line 45
# expected: -1
#      got: -2
# Looks like you failed 2 tests of 21
t/02-keys.t ............... Dubious, test returned 2 (wstat 512, 0x200)
Failed 2/21 subtests 
t/02-lists.t .............. ok     
t/02-pub&sub.t ............ ok   
t/02-scripting.t .......... 1/5 ERR unknown command 'SCRIPT FLUSH'
  in method read_response at /home/jraspass/perl6-redis/lib/Redis.pm line 161
  in method exec_command at /home/jraspass/perl6-redis/lib/Redis.pm line 147
  in method script_flush at /home/jraspass/perl6-redis/lib/Redis.pm line 863
  in block <unit> at t/02-scripting.t line 17

# Looks like you planned 5 tests, but ran 1
t/02-scripting.t .......... Dubious, test returned 255 (wstat 65280, 0xff00)
Failed 4/5 subtests 
t/02-server.t ............. ok   
t/02-sets.t ............... ok     
t/02-sortedsets.t ......... 1/23 Use of uninitialized value $value of type Any in string context
Any of .^name, .perl, .gist, or .say can stringify undefined things, if needed.  in method encode at /home/jraspass/perl6-redis/lib/Redis.pm line 127
ERR syntax error
  in method read_response at /home/jraspass/perl6-redis/lib/Redis.pm line 161
  in method exec_command at /home/jraspass/perl6-redis/lib/Redis.pm line 147
  in method zrange at /home/jraspass/perl6-redis/lib/Redis.pm line 722
  in block <unit> at t/02-sortedsets.t line 28

# Looks like you planned 23 tests, but ran 8
t/02-sortedsets.t ......... Dubious, test returned 255 (wstat 65280, 0xff00)
Failed 15/23 subtests 
t/02-strings.t ............ ok     
t/02-transactions.t ....... ok   
t/03-binary.t ............. ok   
t/03-multibytes.t ......... ok   
t/04-exec-any-commands.t .. ERR unknown command 'CONFIG GET'
  in method read_response at /home/jraspass/perl6-redis/lib/Redis.pm line 161
  in method exec_command at /home/jraspass/perl6-redis/lib/Redis.pm line 147
  in block <unit> at t/04-exec-any-commands.t line 12

t/04-exec-any-commands.t .. Dubious, test returned 255 (wstat 65280, 0xff00)
Failed 1/1 subtests 

Test Summary Report
-------------------
t/02-keys.t             (Wstat: 512 Tests: 21 Failed: 2)
  Failed tests:  12, 14
  Non-zero exit status: 2
t/02-scripting.t        (Wstat: 65280 Tests: 1 Failed: 0)
  Non-zero exit status: 255
  Parse errors: Bad plan.  You planned 5 tests but ran 1.
t/02-sortedsets.t       (Wstat: 65280 Tests: 8 Failed: 0)
  Non-zero exit status: 255
  Parse errors: Bad plan.  You planned 23 tests but ran 8.
t/04-exec-any-commands.t (Wstat: 65280 Tests: 0 Failed: 0)
  Non-zero exit status: 255
  Parse errors: Bad plan.  You planned 1 tests but ran 0.
Files=15, Tests=126,  8 wallclock secs ( 0.06 usr  0.00 sys +  7.58 cusr  0.35 csys =  7.99 CPU)
Result: FAIL

cofyc / perl6-redis

Fix compilation under Perl 6.c #7