title: AC_CANONICAL_HOST autoconf macro is generated outside if conditional in AS_IF
body: <p>I'd like to include in an autotools based project our new machine type, which is not recognized by autoconf macro AC_CANONICAL_HOST (other platforms still need to be treated with it). So I added AS_IF macro to handle it:</p>
  <p><code>AS_IF([test &quot;x$host&quot; == xtachy-linux-gnu], [SET_TACHY], [AC_CANONICAL_HOST])</code></p>
  <p>However, AC_CANONICAL_HOST generated output in <em>configure</em> file is located before <em>if</em> conditional. When I replaced AC_CANONICAL_HOST to anything reasonable, let's say</p>
  <p><code>AS_IF([test &quot;x$host&quot; == xtachy-linux-gnu], [SET_TACHY], [AC_MSG_NOTICE([TACHY_FALSE])])</code></p>
  <p>it works correctly and <em>if</em> conditionial in <em>configure</em> looks fine. Is there any problem placing with AC_CANONICAL_HOST macro in AS_IF?</p>
  <p>Thanks a lot.</p>