menuselect: Remove ineffective weak attribute detection.

menuselect detects compiler support for multiple styles of weak
functions.  This is a remnant from 2013 when OPTIONAL_API required weak
functions.  It is no longer correct for menuselect to switch
dependencies from optional to required based on lack of weak function
support.

Note an issue remains - dependencies should switch from optional to
required based on OPTIONAL_API being enabled or disabled.  I don't think
this is possible.  menuselect needs to know at startup if OPTIONAL_API
is enabled or disabled, so the only way to fix this is to remove
OPTIONAL_API from menuselect and create a configure option.  I've left
the code that switches in place but it's preprocessed out.

Additionally removed:
- WEAKREF variable from Asterisk makeopts.in.
- Related disabled code from test_utils.
- Pointless AC_REVISION call from menuselect/configure.ac.

Change-Id: Ifa702e5f98eb45f338b2f131a93354632a8fb389

tests/test_utils.c

@@ -326,20 +326,6 @@ AST_TEST_DEFINE(crypto_loaded_test)
 		break;
 	}
 
-#if 0 /* Not defined on Solaris */
-	ast_test_status_update(test,
-			       "address of __stub__ast_crypto_loaded is %p\n",
-			       __stub__ast_crypto_loaded);
-#ifndef HAVE_ATTRIBUTE_weak_import
-	ast_test_status_update(test,
-			       "address of __ref__ast_crypto_loaded is %p\n",
-			       __ref__ast_crypto_loaded);
-#endif
-	ast_test_status_update(test,
-			       "pointer to ast_crypto_loaded is %p\n",
-			       ast_crypto_loaded);
-#endif
-
 	return ast_crypto_loaded() ? AST_TEST_PASS : AST_TEST_FAIL;
 }
 
@@ -390,20 +376,6 @@ AST_TEST_DEFINE(agi_loaded_test)
 		break;
 	}
 
-#if 0
-	ast_test_status_update(test,
-			       "address of __stub__ast_agi_register is %p\n",
-			       __stub__ast_agi_register);
-#ifndef HAVE_ATTRIBUTE_weak_import
-	ast_test_status_update(test,
-			       "address of __ref__ast_agi_register is %p\n",
-			       __ref__ast_agi_register);
-#endif
-	ast_test_status_update(test,
-			       "pointer to ast_agi_register is %p\n",
-			       ast_agi_register);
-#endif
-
 	if (ast_agi_register(ast_module_info->self, &noop_command) == AST_OPTIONAL_API_UNAVAILABLE) {
 		ast_test_status_update(test, "Unable to register testnoop command, because res_agi is not loaded.\n");
 		return AST_TEST_FAIL;