Convert paths to POSIX style on Windows and remove spew.
Convert paths to POSIX style on Windows and remove spew.

Avoid a warning generated on WINDOWS by using POSIX style paths as
inputs to GCC tools.  This also removes the excess spew of the
linker options.

TEST= try
BUG= http://code.google.com/p/chromium/issues/detail?id=96782
TRB= bradnelson@chromium.org
Review URL: http://codereview.chromium.org/8306002

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@6940 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client