Further -Wshadow=compatible-local warning fixes

These should have been included in 421892a19 as these shadowed variable
warnings can also be fixed by adjusting the scope of the shadowed variable
to put the declaration for it in an inner scope.

This is part of the same effort as f01592f91.

By my count, this takes the warning count from 114 down to 106.

Author: David Rowley and Justin Pryzby
Discussion: https://postgr.es/m/CAApHDvrwLGBP%2BYw9vriayyf%3DXR4uPWP5jr6cQhP9au_kaDUhbA%40mail.gmail.com

src/backend/access/spgist/spgdoinsert.c

@@ -395,7 +395,6 @@ moveLeafs(Relation index, SpGistState *state,
 				size;
 	Buffer		nbuf;
 	Page		npage;
-	SpGistLeafTuple it;
 	OffsetNumber r = InvalidOffsetNumber,
 				startOffset = InvalidOffsetNumber;
 	bool		replaceDead = false;
@@ -467,6 +466,8 @@ moveLeafs(Relation index, SpGistState *state,
 	{
 		for (i = 0; i < nDelete; i++)
 		{
+			SpGistLeafTuple it;
+
 			it = (SpGistLeafTuple) PageGetItem(current->page,
 											   PageGetItemId(current->page, toDelete[i]));
 			Assert(it->tupstate == SPGIST_LIVE);

src/backend/commands/trigger.c

@@ -1149,7 +1149,6 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
 		PartitionDesc partdesc = RelationGetPartitionDesc(rel, true);
 		List	   *idxs = NIL;
 		List	   *childTbls = NIL;
-		ListCell   *l;
 		int			i;
 		MemoryContext oldcxt,
 					perChildCxt;
@@ -1181,6 +1180,7 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
 		for (i = 0; i < partdesc->nparts; i++)
 		{
 			Oid			indexOnChild = InvalidOid;
+			ListCell   *l;
 			ListCell   *l2;
 			CreateTrigStmt *childStmt;
 			Relation	childTbl;

src/backend/executor/nodeHash.c

@@ -1080,7 +1080,6 @@ static void
 ExecParallelHashIncreaseNumBatches(HashJoinTable hashtable)
 {
 	ParallelHashJoinState *pstate = hashtable->parallel_state;
-	int			i;
 
 	Assert(BarrierPhase(&pstate->build_barrier) == PHJ_BUILD_HASHING_INNER);
 
@@ -1244,7 +1243,7 @@ ExecParallelHashIncreaseNumBatches(HashJoinTable hashtable)
 				ExecParallelHashTableSetCurrentBatch(hashtable, 0);
 
 				/* Are any of the new generation of batches exhausted? */
-				for (i = 0; i < hashtable->nbatch; ++i)
+				for (int i = 0; i < hashtable->nbatch; ++i)
 				{
 					ParallelHashJoinBatch *batch = hashtable->batches[i].shared;
 

src/backend/optimizer/plan/planner.c

@@ -1981,7 +1981,6 @@ preprocess_grouping_sets(PlannerInfo *root)
 	Query	   *parse = root->parse;
 	List	   *sets;
 	int			maxref = 0;
-	ListCell   *lc;
 	ListCell   *lc_set;
 	grouping_sets_data *gd = palloc0(sizeof(grouping_sets_data));
 
@@ -2024,6 +2023,7 @@ preprocess_grouping_sets(PlannerInfo *root)
 	if (!bms_is_empty(gd->unsortable_refs))
 	{
 		List	   *sortable_sets = NIL;
+		ListCell   *lc;
 
 		foreach(lc, parse->groupingSets)
 		{

src/backend/tsearch/ts_typanalyze.c

@@ -161,7 +161,6 @@ compute_tsvector_stats(VacAttrStats *stats,
 	int			vector_no,
 				lexeme_no;
 	LexemeHashKey hash_key;
-	TrackItem  *item;
 
 	/*
 	 * We want statistics_target * 10 lexemes in the MCELEM array.  This
@@ -240,6 +239,7 @@ compute_tsvector_stats(VacAttrStats *stats,
 		curentryptr = ARRPTR(vector);
 		for (j = 0; j < vector->size; j++)
 		{
+			TrackItem  *item;
 			bool		found;
 
 			/*
@@ -296,6 +296,7 @@ compute_tsvector_stats(VacAttrStats *stats,
 		int			nonnull_cnt = samplerows - null_cnt;
 		int			i;
 		TrackItem **sort_table;
+		TrackItem  *item;
 		int			track_len;
 		int			cutoff_freq;
 		int			minfreq,

src/backend/utils/adt/levenshtein.c

@@ -81,8 +81,7 @@ varstr_levenshtein(const char *source, int slen,
 	int		   *prev;
 	int		   *curr;
 	int		   *s_char_len = NULL;
-	int			i,
+	int			j;
-				j;
 	const char *y;
 
 	/*
@@ -217,7 +216,7 @@ varstr_levenshtein(const char *source, int slen,
 	 * To transform the first i characters of s into the first 0 characters of
 	 * t, we must perform i deletions.
 	 */
-	for (i = START_COLUMN; i < STOP_COLUMN; i++)
+	for (int i = START_COLUMN; i < STOP_COLUMN; i++)
 		prev[i] = i * del_c;
 
 	/* Loop through rows of the notional array */
@@ -226,6 +225,7 @@ varstr_levenshtein(const char *source, int slen,
 		int		   *temp;
 		const char *x = source;
 		int			y_char_len = n != tlen + 1 ? pg_mblen(y) : 1;
+		int			i;
 
 #ifdef LEVENSHTEIN_LESS_EQUAL
 

src/backend/utils/adt/rangetypes_gist.c

@@ -1322,8 +1322,7 @@ range_gist_double_sorting_split(TypeCacheEntry *typcache,
 	ConsiderSplitContext context;
 	OffsetNumber i,
 				maxoff;
-	RangeType  *range,
+	RangeType  *left_range = NULL,
-			   *left_range = NULL,
 			   *right_range = NULL;
 	int			common_entries_count;
 	NonEmptyRange *by_lower,
@@ -1518,6 +1517,7 @@ range_gist_double_sorting_split(TypeCacheEntry *typcache,
 	 */
 	for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
 	{
+		RangeType  *range;
 		RangeBound	lower,
 					upper;
 		bool		empty;
@@ -1593,6 +1593,7 @@ range_gist_double_sorting_split(TypeCacheEntry *typcache,
 		 */
 		for (i = 0; i < common_entries_count; i++)
 		{
+			RangeType  *range;
 			int			idx = common_entries[i].index;
 
 			range = DatumGetRangeTypeP(entryvec->vector[idx].key);

src/backend/utils/adt/ruleutils.c

@@ -1615,7 +1615,6 @@ pg_get_statisticsobj_worker(Oid statextid, bool columns_only, bool missing_ok)
 	ArrayType  *arr;
 	char	   *enabled;
 	Datum		datum;
-	bool		isnull;
 	bool		ndistinct_enabled;
 	bool		dependencies_enabled;
 	bool		mcv_enabled;
@@ -1668,6 +1667,8 @@ pg_get_statisticsobj_worker(Oid statextid, bool columns_only, bool missing_ok)
 
 	if (!columns_only)
 	{
+		bool		isnull;
+
 		nsp = get_namespace_name_or_temp(statextrec->stxnamespace);
 		appendStringInfo(&buf, "CREATE STATISTICS %s",
 						 quote_qualified_identifier(nsp,