Enable lex subs everywhere; suppress warning

Adjust tests, too.

Author: Father Chrysostomos

t/lib/croak/toke

@@ -99,29 +99,24 @@ Missing $ on loop variable at - line 1.
 # NAME Missing name in "my sub"
 use feature 'lexical_subs'; my sub;
 EXPECT
-The lexical_subs feature is experimental at - line 1.
 Missing name in "my sub" at - line 1.
 ########
 # NAME Missing name in "our sub"
 use feature 'lexical_subs'; our sub;
 EXPECT
-The lexical_subs feature is experimental at - line 1.
 Missing name in "our sub" at - line 1.
 ########
 # NAME Missing name in "state sub"
-use 5.01; use feature 'lexical_subs';
+use 5.01;
 state sub;
 EXPECT
-The lexical_subs feature is experimental at - line 2.
 Missing name in "state sub" at - line 2.
 ########
 # NAME my sub pack::foo
 use feature 'lexical_subs', 'state';
 my sub foo::bar;
 state sub foo::bear;
 EXPECT
-The lexical_subs feature is experimental at - line 2.
-The lexical_subs feature is experimental at - line 3.
 "my" subroutine &foo::bar can't be in a package at - line 2, near "my sub foo::bar"
 "state" subroutine &foo::bear can't be in a package at - line 3, near "state sub foo::bear"
 Execution of - aborted due to compilation errors.

t/lib/warnings/op

@@ -997,15 +997,11 @@ sub phred { 2 };
 state sub jorge { 1 }
 sub jorge () { 2 } # should *not* produce redef warnings by default
 EXPECT
-The lexical_subs feature is experimental at - line 3.
 Prototype mismatch: sub fred () vs none at - line 4.
 Constant subroutine fred redefined at - line 4.
-The lexical_subs feature is experimental at - line 5.
 Prototype mismatch: sub george: none vs () at - line 6.
-The lexical_subs feature is experimental at - line 7.
 Prototype mismatch: sub phred () vs none at - line 8.
 Constant subroutine phred redefined at - line 8.
-The lexical_subs feature is experimental at - line 9.
 Prototype mismatch: sub jorge: none vs () at - line 10.
 ########
 # op.c

t/lib/warnings/toke

@@ -1228,7 +1228,7 @@ Use of :locked is deprecated at - line 4.
 Use of :locked is deprecated at - line 6.
 ########
 # toke.c
-use warnings "syntax"; use feature 'lexical_subs';
+use warnings "syntax";
 sub proto_after_array(@$);
 sub proto_after_arref(\@$);
 sub proto_after_arref2(\[@$]);
@@ -1257,11 +1257,8 @@ Prototype after '@' for main::proto_after_array : @$ at - line 3.
 Prototype after '%' for main::proto_after_hash : %$ at - line 7.
 Illegal character after '_' in prototype for main::underscore_fail : $_$ at - line 12.
 Prototype after '@' for main::underscore_after_at : @_ at - line 13.
-The lexical_subs feature is experimental at - line 14.
 Prototype after '@' for hour : @$ at - line 14.
-The lexical_subs feature is experimental at - line 15.
 Prototype after '@' for migh : @$ at - line 15.
-The lexical_subs feature is experimental at - line 17.
 Prototype after '@' for estate : @$ at - line 17.
 Prototype after '@' for hour : @$ at - line 19.
 Prototype after '@' for migh : @$ at - line 20.

t/op/lexsub.t

@@ -7,24 +7,10 @@ BEGIN {
     *bar::is = *is;
     *bar::like = *like;
 }
-plan 152;
-
-# -------------------- Errors with feature disabled -------------------- #
-
-eval "#line 8 foo\nmy sub foo";
-is $@, qq 'Experimental "my" subs not enabled at foo line 8.\n',
-  'my sub unexperimental error';
-eval "#line 8 foo\nCORE::state sub foo";
-is $@, qq 'Experimental "state" subs not enabled at foo line 8.\n',
-  'state sub unexperimental error';
-eval "#line 8 foo\nour sub foo";
-is $@, qq 'Experimental "our" subs not enabled at foo line 8.\n',
-  'our sub unexperimental error';
+plan 149;
 
 # -------------------- our -------------------- #
 
-no warnings "experimental::lexical_subs";
-use feature 'lexical_subs';
 {
   our sub foo { 42 }
   is foo, 42, 'calling our sub from same package';

toke.c

@@ -7781,17 +7781,7 @@ Perl_yylex(pTHX)
 	    if (isIDFIRST_lazy_if(s,UTF)) {
 		s = scan_word(s, PL_tokenbuf, sizeof PL_tokenbuf, TRUE, &len);
 		if (len == 3 && strnEQ(PL_tokenbuf, "sub", 3))
-		{
-		    if (!FEATURE_LEXSUBS_IS_ENABLED)
-			Perl_croak(aTHX_
-				  "Experimental \"%s\" subs not enabled",
-				   tmp == KEY_my    ? "my"    :
-				   tmp == KEY_state ? "state" : "our");
-		    Perl_ck_warner_d(aTHX_
-			packWARN(WARN_EXPERIMENTAL__LEXICAL_SUBS),
-			"The lexical_subs feature is experimental");
 		    goto really_sub;
-		}
 		PL_in_my_stash = find_in_my_stash(PL_tokenbuf, len);
 		if (!PL_in_my_stash) {
 		    char tmpbuf[1024];