Change how we handle alloca to conform with how it is suggested in the...

Change how we handle alloca to conform with how it is suggested in the autoconf manual for AC_FUNC_ALLOCA. FreeBSD 6 now builds again and no other platforms should be broken by this.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89396 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/compat.h

@@ -52,9 +52,14 @@
 #endif
 
 #ifdef HAVE_ALLOCA_H
-#include <alloca.h>	/* not necessarily present - could be in stdlib */
-#elif defined(HAVE_ALLOCA)
-#include <malloc.h>	/* see if it is here... */
+#include <alloca.h>
+#elif defined(__GNUC__)
+#define alloca __builtin_alloca
+#elif defined(_AIX)
+#define alloca __alloca
+#elif defined(_MSC_VER)
+#include <malloc.h>
+#define alloca _alloca
 #endif
 
 #include <stdio.h>	/* this is always present */