[sldev] cygwin flex lscript_compile workaround

[Steve]

I'm not sure whether this has already been addressed here, but we 
discovered a problem with the latest version of Cygwin flex and 
lscript_compile and I thought I would share the workaround. We've 
committed the workaround to our release-candidate branche so it should 
be in an upcoming source drop as well.

1. Add "YY_NO_UNISTD_H" to the list of Preprocessor Definitions in the 
lscript_compile project file.
2. Apply the following patch it indra.l:

Index: indra.l
===================================================================
--- indra.l    (revision 86342)
+++ indra.l    (revision 86343)
@@ -12,6 +12,7 @@
 #include "linden_common.h"
 // Deal with the fact that lex/yacc generates unreachable code
 #ifdef LL_WINDOWS
+#pragma warning (disable : 4018) // warning C4018: signed/unsigned mismatch
 #pragma warning (disable : 4702) // warning C4702: unreachable code
 #endif    //    LL_WINDOWS
 #include "llmath.h"
@@ -44,7 +45,10 @@
 
 #define YYLMAX 16384
 #define YY_NEVER_INTERACTIVE 1 /* stops flex from calling isatty() */
-
+#ifdef LL_WINDOWS
+#define isatty(x) 0 /* hack for bug in cygwin flex 2.5.35 */
+#endif
+
 #ifdef ECHO
 #undef ECHO
 #endif