use alloca on unix, malloc / free on win32
use alloca on unix, malloc / free on win32

git-svn-id: bfcfd16de7ad3adcb7c950718a3d167d8c2ea482@263 4d3e2a30-9d6d-0410-bc8c-dac56cff10b3

kazuho/incline,kazuho/incline,kazuho/incline