[PATH] spell.c (avoid call strlen repeatedly in loop.

Hi Mark,
Another example, can you take a look?

--- \dll\postgresql-12.0\a\backend\tsearch\spell.c	Mon Sep 30 17:06:55 2019
+++ spell.c	Sat Nov 09 05:55:23 2019
@@ -186,7 +186,7 @@
 #define MAX_NORM 1024
 #define MAXNORMLEN 256

-#define STRNCMP(s,p)	strncmp( (s), (p), strlen(p) )
+#define STRNCMP(s,p)	strncmp( (s), (p), sizeof(p) - 1 )
 #define GETWCHAR(W,L,N,T) ( ((const uint8*)(W))[ ((T)==FF_PREFIX) ? (N) : ( (L) - 1 - (N) ) ] )
 #define GETCHAR(A,N,T)	  GETWCHAR( (A)->repl, (A)->replen, N, T )

@@ -1220,31 +1220,31 @@
}

 		if (STRNCMP(recoded, "COMPOUNDFLAG") == 0)
-			addCompoundAffixFlagValue(Conf, recoded + strlen("COMPOUNDFLAG"),
+			addCompoundAffixFlagValue(Conf, recoded + sizeof("COMPOUNDFLAG") - 1,
 									  FF_COMPOUNDFLAG);
 		else if (STRNCMP(recoded, "COMPOUNDBEGIN") == 0)
-			addCompoundAffixFlagValue(Conf, recoded + strlen("COMPOUNDBEGIN"),
+			addCompoundAffixFlagValue(Conf, recoded + sizeof("COMPOUNDBEGIN") - 1,
 									  FF_COMPOUNDBEGIN);
 		else if (STRNCMP(recoded, "COMPOUNDLAST") == 0)
-			addCompoundAffixFlagValue(Conf, recoded + strlen("COMPOUNDLAST"),
+			addCompoundAffixFlagValue(Conf, recoded + sizeof("COMPOUNDLAST") - 1,
 									  FF_COMPOUNDLAST);
 		/* COMPOUNDLAST and COMPOUNDEND are synonyms */
 		else if (STRNCMP(recoded, "COMPOUNDEND") == 0)
-			addCompoundAffixFlagValue(Conf, recoded + strlen("COMPOUNDEND"),
+			addCompoundAffixFlagValue(Conf, recoded + sizeof("COMPOUNDEND") - 1,
 									  FF_COMPOUNDLAST);
 		else if (STRNCMP(recoded, "COMPOUNDMIDDLE") == 0)
-			addCompoundAffixFlagValue(Conf, recoded + strlen("COMPOUNDMIDDLE"),
+			addCompoundAffixFlagValue(Conf, recoded + sizeof("COMPOUNDMIDDLE") - 1,
 									  FF_COMPOUNDMIDDLE);
 		else if (STRNCMP(recoded, "ONLYINCOMPOUND") == 0)
-			addCompoundAffixFlagValue(Conf, recoded + strlen("ONLYINCOMPOUND"),
+			addCompoundAffixFlagValue(Conf, recoded + sizeof("ONLYINCOMPOUND") - 1,
 									  FF_COMPOUNDONLY);
 		else if (STRNCMP(recoded, "COMPOUNDPERMITFLAG") == 0)
 			addCompoundAffixFlagValue(Conf,
-									  recoded + strlen("COMPOUNDPERMITFLAG"),
+									  recoded + sizeof("COMPOUNDPERMITFLAG") - 1,
 									  FF_COMPOUNDPERMITFLAG);
 		else if (STRNCMP(recoded, "COMPOUNDFORBIDFLAG") == 0)
 			addCompoundAffixFlagValue(Conf,
-									  recoded + strlen("COMPOUNDFORBIDFLAG"),
+									  recoded + sizeof("COMPOUNDFORBIDFLAG") - 1,
 									  FF_COMPOUNDFORBIDFLAG);
 		else if (STRNCMP(recoded, "FLAG") == 0)
 		{