Add documentation for ASN1_INTEGER_new() and ASN1_INTEGER_free()

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/11795)

doc/man3/ASN1_INTEGER_new.pod

@@ -0,0 +1,44 @@
+=pod
+
+=head1 NAME
+
+ASN1_INTEGER_new, ASN1_INTEGER_free - ASN1_INTEGER allocation functions
+
+=head1 SYNOPSIS
+
+=for openssl generic
+
+ #include <openssl/asn1.h>
+
+ ASN1_INTEGER *ASN1_INTEGER_new(void);
+ void ASN1_INTEGER_free(ASN1_INTEGER *a);
+
+=head1 DESCRIPTION
+
+ASN1_INTEGER_new() returns an allocated B<ASN1_INTEGER> structure.
+
+ASN1_INTEGER_free() frees up a single B<ASN1_INTEGER> object.
+
+B<ASN1_INTEGER> structure representing the ASN.1 INTEGER type
+
+=head1 RETURN VALUES
+
+ASN1_INTEGER_new() return a valid B<ASN1_INTEGER> structure or NULL
+if an error occurred.
+
+ASN1_INTEGER_free() does not return a value.
+
+=head1 SEE ALSO
+
+L<ERR_get_error(3)>
+
+=head1 COPYRIGHT
+
+Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the Apache License 2.0 (the "License").  You may not use
+this file except in compliance with the License.  You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
+
+=cut

util/missingcrypto.txt

@@ -49,9 +49,7 @@ ASN1_IA5STRING_it(3)
 ASN1_IA5STRING_new(3)
 ASN1_INTEGER_cmp(3)
 ASN1_INTEGER_dup(3)
-ASN1_INTEGER_free(3)
 ASN1_INTEGER_it(3)
-ASN1_INTEGER_new(3)
 ASN1_NULL_free(3)
 ASN1_NULL_it(3)
 ASN1_NULL_new(3)