Add patch headers

Also cleanup the flex patch a bit

sysa/flex-2.5.11/patches/scan_l.patch

@@ -1,15 +1,9 @@
+Comments are unsupported by our flex.
+
 diff --git scan.l scan.l
 index 18d0de8..c251a5e 100644
 --- scan.l
 +++ scan.l
-@@ -32,6 +32,7 @@
- /*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
- /*  PURPOSE. */
- 
-+#define yyin_defined
- #include "flexdef.h"
- #include "parse.h"
- 
 @@ -334,8 +335,8 @@ LEXOPT		[aceknopr]
  
  

sysa/flex-2.5.11/patches/yyin.patch

@@ -1,3 +1,6 @@
+yyin has an odd redefinition error in scan.l, so we ensure that we don't
+acidentally re-declare it.
+
 diff --git flexdef.h flexdef.h
 index 3eb710a..94ef024 100644
 --- flexdef.h
@@ -22,3 +25,13 @@ index 3eb710a..94ef024 100644
  extern char *action_array;
  extern int action_size;
  extern int defs1_offset, prolog_offset, action_offset, action_index;
+--- scan.l
++++ scan.l
+@@ -32,6 +32,7 @@
+ /*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
+ /*  PURPOSE. */
+ 
++#define yyin_defined
+ #include "flexdef.h"
+ #include "parse.h"
+