Fix portability issue in isolationtester grammar.

specparse.y and specscanner.l used "string" as a token name.  Now, bison
likes to define each token name as a macro for the token code it assigns,
which means those names are basically off-limits for any other use within
the grammar file or included headers.  So names as generic as "string" are
dangerous.  This is what was causing the recent failures on protosciurus:
some versions of Solaris' sys/kstat.h use "string" as a field name.
With late-model bison we don't see this problem because the token macros
aren't defined till later (that is why castoroides didn't show the problem
even though it's on the same machine).  But protosciurus uses bison 1.875
which defines the token macros up front.

This land mine has been there from day one; we'd have found it sooner
except that protosciurus wasn't trying to run the isolation tests till
recently.

To fix, rename the token to "string_literal" which is hopefully less
likely to collide with names used by system headers.  Back-patch to
all branches containing the isolation tests.

src/test/isolation/specparse.y

@@ -39,12 +39,12 @@ TestSpec		parseresult;			/* result of parsing is left here */
 %type <str>  opt_setup opt_teardown
 %type <str> setup
 %type <ptr_list> step_list session_list permutation_list opt_permutation_list
-%type <ptr_list> string_list
+%type <ptr_list> string_literal_list
 %type <session> session
 %type <step> step
 %type <permutation> permutation
 
-%token <str> sqlblock string
+%token <str> sqlblock string_literal
 %token PERMUTATION SESSION SETUP STEP TEARDOWN TEST
 
 %%
@@ -111,7 +111,7 @@ session_list:
 		;
 
 session:
-			SESSION string opt_setup step_list opt_teardown
+			SESSION string_literal opt_setup step_list opt_teardown
 			{
 				$$ = malloc(sizeof(Session));
 				$$->name = $2;
@@ -140,7 +140,7 @@ step_list:
 
 
 step:
-			STEP string sqlblock
+			STEP string_literal sqlblock
 			{
 				$$ = malloc(sizeof(Step));
 				$$->name = $2;
@@ -179,7 +179,7 @@ permutation_list:
 
 
 permutation:
-			PERMUTATION string_list
+			PERMUTATION string_literal_list
 			{
 				$$ = malloc(sizeof(Permutation));
 				$$->stepnames = (char **) $2.elements;
@@ -187,15 +187,15 @@ permutation:
 			}
 		;
 
-string_list:
-			string_list string
+string_literal_list:
+			string_literal_list string_literal
 			{
 				$$.elements = realloc($1.elements,
 									  ($1.nelements + 1) * sizeof(void *));
 				$$.elements[$1.nelements] = $2;
 				$$.nelements = $1.nelements + 1;
 			}
-			| string
+			| string_literal
 			{
 				$$.nelements = 1;
 				$$.elements = malloc(sizeof(void *));

src/test/isolation/specscanner.l

@@ -58,7 +58,7 @@ teardown		{ return(TEARDOWN); }
 					litbuf[litbufpos] = '\0';
 					yylval.str = strdup(litbuf);
 					BEGIN(INITIAL);
-					return(string);
+					return(string_literal);
 				}
 <qstr>.			{ addlitchar(yytext[0]); }
 <qstr>\n		{ yyerror("unexpected newline in quoted string"); }