Revert "Warn EOF char in comment"

This reverts commit 69ec3f70fa.

parse.y

@@ -6191,30 +6191,7 @@ parser_str_new(const char *ptr, long len, rb_encoding *enc, int func, rb_encodin
     return str;
 }
 
-static const char *
-eof_char(int c)
-{
-    switch (c) {
-      case '\0': return "\\0";
-      case '\004': return "^D";
-      case '\032': return "^Z";
-    }
-    return 0;
-}
-
-static void
-lex_goto_eol(struct parser_params *p)
-{
-    const char *pcur = p->lex.pcur, *pend = p->lex.pend;
-    for (; pcur < pend; pcur++) {
-        const char *eof = eof_char(*pcur);
-        if (eof) {
-            rb_warning1("encountered %s in comment, just ignored in this version", WARN_S(eof));
-            break;
-        }
-    }
-    p->lex.pcur = pend;		/* pcur */
-}
+#define lex_goto_eol(p) ((p)->lex.pcur = (p)->lex.pend)
 #define lex_eol_p(p) ((p)->lex.pcur >= (p)->lex.pend)
 #define lex_eol_n_p(p,n) ((p)->lex.pcur+(n) >= (p)->lex.pend)
 #define peek(p,c) peek_n(p, (c), 0)
@@ -7421,7 +7398,9 @@ word_match_p(struct parser_params *p, const char *word, long len)
     if (p->lex.pcur + len == p->lex.pend) return 1;
     int c = (unsigned char)p->lex.pcur[len];
     if (ISSPACE(c)) return 1;
-    if (eof_char(c)) return 1;
+    switch (c) {
+      case '\0': case '\004': case '\032': return 1;
+    }
     return 0;
 }
 

test/ruby/test_parse.rb

@@ -720,15 +720,6 @@ x = __ENCODING__
     assert_syntax_error("=begin", error)
   end
 
-  def test_embedded_rd_warning
-    [["\0", "\\0"], ["\C-d", "^D"], ["\C-z", "^Z"]].each do |eof, mesg|
-      mesg = /encountered #{Regexp.quote(mesg)}/
-      assert_warning(mesg) {eval("=begin\n#{eof}\n=end")}
-      assert_warning(mesg) {eval("=begin#{eof}\n=end")}
-      assert_warning(mesg) {eval("=begin\n=end#{eof}\n")}
-    end
-  end
-
   def test_float
     assert_equal(1.0/0, eval("1e10000"))
     assert_syntax_error('1_E', /trailing `_'/)

test/ruby/test_syntax.rb

@@ -943,12 +943,6 @@ eom
     end
   end
 
-  def test_warning_for_eof_in_comment
-    assert_warning(/encountered \\0/) {eval("#\0")}
-    assert_warning(/encountered \^D/) {eval("#\C-d")}
-    assert_warning(/encountered \^Z/) {eval("#\C-z")}
-  end
-
   def test_unexpected_fraction
     msg = /unexpected fraction/
     assert_syntax_error("0x0.0", msg)