Config.xs syntax error on windows

[rurban]

E.g. https://ci.appveyor.com/project/rurban/cperl/build/job/0yfvf5sqe7sisxrs

ext/Config/Config_xs.in(1149) : warning C4129: 'p' : unrecognized character escape sequence 
ext/Config/Config_xs.in(1149) : warning C4129: 's' : unrecognized character escape sequence 
ext/Config/Config_xs.in(1149) : warning C4129: 'l' : unrecognized character escape sequence 
ext/Config/Config_xs.in(1113) : warning C4129: 'p' : unrecognized character escape sequence 
ext/Config/Config_xs.in(917) : warning C4129: 'i' : unrecognized character escape sequence 
ext/Config/Config_xs.in(1006) : warning C4129: 'p' : unrecognized character escape sequence 
ext/Config/Config_xs.in(1006) : warning C4129: 'm' : unrecognized character escape sequence 
ext/Config/Config_xs.in(1009) : warning C4129: 'p' : unrecognized character escape sequence 
ext/Config/Config_xs.in(1009) : warning C4129: 'm' : unrecognized character escape sequence 
ext/Config/Config_xs.in(930) : warning C4129: 'p' : unrecognized character escape sequence 
ext/Config/Config_xs.in(957) : error C2059: syntax error : ',' 
ext/Config/Config_xs.in(411) : fatal error C1013: compiler limit : too many open parentheses 
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\BIN\amd64\cl.EXE"' : return code '0x2'
Stop.

[bulk88]

I have a fix for the syntax error but not c escape warnings in #79

The c escape warnings are obviously Win32 file paths in Config.pm/heavy.pm

[rurban]

Not bad: https://ci.appveyor.com/project/rurban/cperl/build/5.22.2.607/job/4u6avr98aeu6nei6

Test Summary Report 
-------------------
comp/require.t                                                  (Wstat: 0 Tests: 58 Failed: 1)
  Failed test:  53
../cpan/Time-Piece/t/02core_dst.t                               (Wstat: 512 Tests: 60 Failed: 2)
  Failed tests:  55-56
  Non-zero exit status: 2
../dist/Storable/t/compat01.t                                   (Wstat: 1536 Tests: 6 Failed: 6)
  Failed tests:  1-6
  Non-zero exit status: 6
../dist/Storable/t/file_magic.t                                 (Wstat: 512 Tests: 79 Failed: 2)
  Failed tests:  6, 14
  Non-zero exit status: 2
../dist/Storable/t/interwork56.t                                (Wstat: 256 Tests: 30 Failed: 1)
  Failed test:  1
  Non-zero exit status: 1
../dist/Storable/t/malice.t                                     (Wstat: 512 Tests: 1 Failed: 0)
  Non-zero exit status: 2
  Parse errors: Bad plan.  You planned 404 tests but ran 1.
../ext/Config/Config.t                                          (Wstat: 0 Tests: 189 Failed: 1)
  Failed test:  20
../ext/Config/t/Config.t                                        (Wstat: 512 Tests: 4 Failed: 2)
  Failed tests:  3-4
  Non-zero exit status: 2
Files=2397, Tests=708037, 1325 wallclock secs (87.69 usr +  4.16 sys = 91.84 CPU)
Result: FAIL
NMAKE : fatal error U1077: '.\perl.exe' : return code '0xf'
Stop.