neverparse: accept more unparenthesised guards

Also accept guards of the form (a) || !(b) or (a) && !(b).

* src/neverparse/neverclaimscan.ll: Adjust.
* src/tgbatest/neverclaimread.test: Add a test case.

src/neverparse/neverclaimscan.ll

@@ -75,7 +75,7 @@ eol      \n|\r|\n\r|\r\n
 			  yylval->str->append(yytext, yyleng);
 			}
          /* if we match ")&&(" or ")||(", stay in <in_par> mode */
-         ")"[ \t]*("&&"|"||")[ \t]*"(" {
+         ")"[ \t]*("&&"|"||")[ \t!]*"(" {
 	                  yylval->str->append(yytext, yyleng);
 			}
 	 ")"		{

src/tgbatest/neverclaimread.test

@@ -117,7 +117,8 @@ cat >input <<EOF
 never { /* p0 || p1  */
 accept_init:
         if
-        :: (p1) || (p0) -> goto accept_all
+        :: (p1) && (p0) -> goto accept_all
+        :: (p1) && !(p0) -> goto accept_all
         fi;
 accept_all:
         skip
@@ -130,20 +131,16 @@ digraph G {
   0 [label="", style=invis, height=0]
   0 -> 1
   1 [label="accept_init", peripheries=2]
-  1 -> 2 [label="p1 | p0\n{Acc[1]}"]
+  1 -> 2 [label="p1\n{Acc[1]}"]
   2 [label="accept_all", peripheries=2]
   2 -> 2 [label="1\n{Acc[1]}"]
 }
 EOF
 
-# Sort out some possible inversions in the output.
-# (The order is not guaranteed by SPOT.)
-sed -e 's/p0 | p1/p1 | p0/g' stdout > tmp_ && mv tmp_ stdout
 diff stdout expected
 
 rm input stdout expected
 
-
 # Test broken guards in input
 cat >input <<EOF
 never {