[PlSql] Handle procedure_spec before variable_declaration (#3818)

To avoid parsing procedure specs without arguments as variable
declarations.

Author: Martin Karlgren

sql/plsql/PlSqlParser.g4

@@ -611,12 +611,12 @@ create_package_body
 package_obj_spec
     : pragma_declaration
     | exception_declaration
+    | procedure_spec
+    | function_spec
     | variable_declaration
     | subtype_declaration
     | cursor_declaration
     | type_declaration
-    | procedure_spec
-    | function_spec
     ;
 
 procedure_spec
@@ -631,14 +631,14 @@ function_spec
 package_obj_body
     : pragma_declaration
     | exception_declaration
+    | procedure_spec
+    | function_spec
     | subtype_declaration
     | cursor_declaration
     | variable_declaration
     | type_declaration
     | procedure_body
     | function_body
-    | procedure_spec
-    | function_spec
     ;
 
 // https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/alter-pmem-filestore.html
@@ -5285,12 +5285,12 @@ seq_of_declare_specs
 declare_spec
     : pragma_declaration
     | exception_declaration
+    | procedure_spec
+    | function_spec
     | variable_declaration
     | subtype_declaration
     | cursor_declaration
     | type_declaration
-    | procedure_spec
-    | function_spec
     | procedure_body
     | function_body
     ;

sql/plsql/examples-sql-script/declare_procedure_no_args.sql

@@ -0,0 +1,13 @@
+declare
+    procedure proc;
+    var number;
+begin
+    null;
+end;
+/
+
+create or replace package pkg is
+    procedure proc;
+    var number;
+end pkg;
+/