Linux sandbox: add space for 8 parameters to the Syscall() class

On some architectures (Mips for example) syscalls can take more
than six parameters.

Add support for 8 native-size parameters in Syscall::Call()

BUG=369594
TEST= sandbox_linux_unittests

Review URL: https://codereview.chromium.org/357323003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@281823 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed