Reduce false positives for @hsh{$s} and @ary[$s] warnings

This resolves tickets #28380 and #114024.

Commit 95a31aad5 did something similar to this for the new %hash{...}
syntax.  This commit extends it to @ slices and combines the two
code paths.

The heuristics in toke.c can easily produce false positives.  So the
op is flagged as being a candidate for the warning.  Then when op.c
has the op tree available, it examines it to see whether the heuristic
may have been a false positive.

This avoids bugs with qw "foo bar baz" and sub calls triggering
the warning.

The source code is no longer available for the warning, so we recon-
struct it from the op tree, skipping the subscript if it is anything
other than a const op.

This means that @hash{$foo} comes out as @hash{...} and @hash{foo} as
@hash{"foo"}.  It also meeans that @hash{"]"} is displayed correctly
instead of as @hash{"].

Commit 95a31aad5 also modified the heuristic for %hash{...} to exempt
qw altogether.  But it did not exempt it if it was preceded by a tab.
So this commit rectifies that.

This commit also improves the false positive detection by exempting
any ops returning lists that can get past toke.c’s heuristic.  I went
through the entire list of ops, but I may have missed some.

Also, @ slices on the lhs of = are exempt, as they change the context
and are hence actually useful.

1 files changed, 7 insertions, 7 deletions

diff --git a/perly.tab b/perly.tab
index fc94499f32..38cae237b8 100644
--- a/perly.tab
+++ b/perly.tab
@@ -197,12 +197,12 @@ static const yytype_uint16 yyrline[] =
     1030,  1037,  1041,  1045,  1050,  1055,  1060,  1069,  1074,  1079,
     1085,  1091,  1102,  1106,  1110,  1122,  1135,  1143,  1155,  1156,
     1157,  1158,  1159,  1164,  1168,  1170,  1174,  1179,  1181,  1186,
-    1188,  1190,  1192,  1194,  1196,  1198,  1207,  1219,  1230,  1244,
-    1246,  1248,  1253,  1266,  1271,  1276,  1280,  1284,  1288,  1292,
-    1296,  1300,  1304,  1306,  1309,  1313,  1319,  1321,  1326,  1329,
-    1338,  1345,  1344,  1360,  1361,  1362,  1368,  1372,  1380,  1387,
-    1392,  1397,  1399,  1401,  1406,  1408,  1413,  1414,  1420,  1424,
-    1430,  1436,  1442,  1449,  1455,  1462,  1464,  1466,  1469
+    1188,  1190,  1192,  1194,  1196,  1198,  1210,  1222,  1236,  1250,
+    1252,  1254,  1259,  1272,  1277,  1282,  1286,  1290,  1294,  1298,
+    1302,  1306,  1310,  1312,  1315,  1319,  1325,  1327,  1332,  1335,
+    1344,  1351,  1350,  1366,  1367,  1368,  1374,  1378,  1386,  1393,
+    1398,  1403,  1405,  1407,  1412,  1414,  1419,  1420,  1426,  1430,
+    1436,  1442,  1449,  1456,  1462,  1469,  1471,  1473,  1476
 };
 #endif
 
@@ -1123,6 +1123,6 @@ static const toketypes yy_type_tab[] =
 };
 
 /* Generated from:
- * 80609b739b642fa427503886445869dfd47021624a1977b902211b38043ed9f1 perly.y
+ * 5b290f371f373fb17e073f602c676e436e9d457a1d4db67d192e3cfa0eeb36d7 perly.y
  * 5c9d2a0262457fe9b70073fc8ad6c188f812f38ad57712b7e2f53daa01b297cc regen_perly.pl
  * ex: set ro: */