Remove unnecessary #ifdef USE_ICU and branch.

Now that the provider-independent API pg_strnxfrm() is available, we
no longer need the special cases for ICU in hashfunc.c and varchar.c.

Reviewed-by: Peter Eisentraut, Peter Geoghegan
Discussion: https://postgr.es/m/a581136455c940d7bd0ff482d3a2bd51af25a94f.camel%40j-davis.com

src/backend/access/hash/hashfunc.c

@@ -288,15 +288,13 @@ hashtext(PG_FUNCTION_ARGS)
 						  VARSIZE_ANY_EXHDR(key));
 	}
 	else
-	{
-#ifdef USE_ICU
-		if (mylocale->provider == COLLPROVIDER_ICU)
 	{
 		Size		bsize, rsize;
 		char	   *buf;
 		const char *keydata = VARDATA_ANY(key);
 		size_t		keylen = VARSIZE_ANY_EXHDR(key);
 
+
 		bsize = pg_strnxfrm(NULL, 0, keydata, keylen, mylocale);
 		buf = palloc(bsize + 1);
 
@@ -313,11 +311,6 @@ hashtext(PG_FUNCTION_ARGS)
 
 		pfree(buf);
 	}
-		else
-#endif
-			/* shouldn't happen */
-			elog(ERROR, "unsupported collprovider: %c", mylocale->provider);
-	}
 
 	/* Avoid leaking memory for toasted inputs */
 	PG_FREE_IF_COPY(key, 0);
@@ -349,9 +342,6 @@ hashtextextended(PG_FUNCTION_ARGS)
 								   PG_GETARG_INT64(1));
 	}
 	else
-	{
-#ifdef USE_ICU
-		if (mylocale->provider == COLLPROVIDER_ICU)
 	{
 		Size		bsize, rsize;
 		char	   *buf;
@@ -375,11 +365,6 @@ hashtextextended(PG_FUNCTION_ARGS)
 
 		pfree(buf);
 	}
-		else
-#endif
-			/* shouldn't happen */
-			elog(ERROR, "unsupported collprovider: %c", mylocale->provider);
-	}
 
 	PG_FREE_IF_COPY(key, 0);
 

src/backend/utils/adt/varchar.c

@@ -1020,9 +1020,6 @@ hashbpchar(PG_FUNCTION_ARGS)
 		result = hash_any((unsigned char *) keydata, keylen);
 	}
 	else
-	{
-#ifdef USE_ICU
-		if (mylocale->provider == COLLPROVIDER_ICU)
 	{
 		Size		bsize, rsize;
 		char	   *buf;
@@ -1043,11 +1040,6 @@ hashbpchar(PG_FUNCTION_ARGS)
 
 		pfree(buf);
 	}
-		else
-#endif
-			/* shouldn't happen */
-			elog(ERROR, "unsupported collprovider: %c", mylocale->provider);
-	}
 
 	/* Avoid leaking memory for toasted inputs */
 	PG_FREE_IF_COPY(key, 0);
@@ -1083,9 +1075,6 @@ hashbpcharextended(PG_FUNCTION_ARGS)
 								   PG_GETARG_INT64(1));
 	}
 	else
-	{
-#ifdef USE_ICU
-		if (mylocale->provider == COLLPROVIDER_ICU)
 	{
 		Size		bsize, rsize;
 		char	   *buf;
@@ -1107,11 +1096,6 @@ hashbpcharextended(PG_FUNCTION_ARGS)
 
 		pfree(buf);
 	}
-		else
-#endif
-			/* shouldn't happen */
-			elog(ERROR, "unsupported collprovider: %c", mylocale->provider);
-	}
 
 	PG_FREE_IF_COPY(key, 0);