Rename comparePos() to compareWordEntryPos()

Rename comparePos() to compareWordEntryPos() to prevent export of too
generic name.

Per gripe from Tom Lane.

src/backend/utils/adt/tsvector.c

@@ -29,7 +29,7 @@ typedef struct
 
 /* Compare two WordEntryPos values for qsort */
 int
-comparePos(const void *a, const void *b)
+compareWordEntryPos(const void *a, const void *b)
 {
 	int			apos = WEP_GETPOS(*(const WordEntryPos *) a);
 	int			bpos = WEP_GETPOS(*(const WordEntryPos *) b);
@@ -54,7 +54,7 @@ uniquePos(WordEntryPos *a, int l)
 	if (l <= 1)
 		return l;
 
-	qsort((void *) a, l, sizeof(WordEntryPos), comparePos);
+	qsort((void *) a, l, sizeof(WordEntryPos), compareWordEntryPos);
 
 	res = a;
 	ptr = a + 1;

src/backend/utils/adt/tsvector_op.c

@@ -1216,7 +1216,7 @@ uniqueLongPos(WordEntryPos *pos, int npos)
 	if (npos <= 1)
 		return npos;
 
-	qsort((void *) pos, npos, sizeof(WordEntryPos), comparePos);
+	qsort((void *) pos, npos, sizeof(WordEntryPos), compareWordEntryPos);
 
 	result = pos;
 	pos_iter = pos + 1;

src/include/tsearch/ts_type.h

@@ -49,7 +49,7 @@ typedef struct
 #define MAXSTRLEN ( (1<<11) - 1)
 #define MAXSTRPOS ( (1<<20) - 1)
 
-extern int comparePos(const void *a, const void *b);
+extern int compareWordEntryPos(const void *a, const void *b);
 
 /*
  * Equivalent to