Ruby » Ruby master

merges r31351 and r31352 from trunk into ruby_1_9_2.¶

• include/ruby/win32.h (ftruncate, truncate, ftello, fseeko): non-64
  versions on mingw are useless because they use int32_t. fixes #4564
  --
• file.c (rb_file_truncate): fix function.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@31817 b2dd03c8-39d4-4d8f-98ff-823fe69b080e