Merge unneeded state with it's parent rule

The `blockname` state did not have a `#pop` after it's only rule,
which caused outputting errors in pygments#2094.

Instead of adding a `#pop`, I merged the `blockname` state with the
rule that uses it, to achieve the exact same lexing logic, but without
another state in the lexer.

pygments/lexers/configs.py

@@ -715,20 +715,15 @@ def heredoc_callback(self, match, ctx):
 
             # e.g. resource "aws_security_group" "allow_tls" {
             # e.g. backend "consul" {
-            (classes_re + r'(\s+)', bygroups(Keyword.Reserved, Whitespace), 'blockname'),
+            (classes_re + r'(\s+)("[0-9a-zA-Z-_]+")?(\s*)("[0-9a-zA-Z-_]+")(\s+)(\{)',
+             bygroups(Keyword.Reserved, Whitespace, Name.Class, Whitespace, Name.Variable, Whitespace, Punctuation)),
 
             # here-doc style delimited strings
             (
                 r'(<<-?)\s*([a-zA-Z_]\w*)(.*?\n)',
                 heredoc_callback,
             )
         ],
-        'blockname': [
-            # e.g. resource "aws_security_group" "allow_tls" {
-            # e.g. backend "consul" {
-            (r'(\s*)("[0-9a-zA-Z-_]+")?(\s*)("[0-9a-zA-Z-_]+")(\s+)(\{)',
-             bygroups(Whitespace, Name.Class, Whitespace, Name.Variable, Whitespace, Punctuation)),
-        ],
         'identifier': [
             (r'\b(var\.[0-9a-zA-Z-_\.\[\]]+)\b', bygroups(Name.Variable)),
             (r'\b([0-9a-zA-Z-_\[\]]+\.[0-9a-zA-Z-_\.\[\]]+)\b', bygroups(Name.Variable)),