Fixes the build for the shell on illumos and Solaris. -D__C99FEATURES__ was added to mirror how the build is done on the normal platform. The changes in the platform code are a follow up to a prior review and has the Solaris implementation be more similar to the Linux version as opposed to the FreeBSD.

Contributed by Robert Mustacchi <rm@fingolfin.org>

TEST=Note the test suite uncovered a bug in libm where pow(3M) was not doing the right thing on edge cases. The only test failures are related to this bug.

Review URL: http://codereview.chromium.org/7282034

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8502 ce2b1a6d-e550-0410-aec6-3dcde31c8c00