* libguile/eval.c (s_bad_formals, s_bad_formal, s_duplicate_formal):

	* libguile/eval.c (s_bad_formals, s_bad_formal, s_duplicate_formal):
        New static identifiers.

	(s_clauses, s_formals, s_duplicate_formals): Removed.

	(scm_m_lambda): Use ASSERT_SYNTAX to signal syntax errors.  Be more
	specific about the kind of error that was detected.  Prepare for
	easier integration of changes for separated memoization.

	* test-suite/tests/syntax.test (define exception:bad-formal, define
	exception:duplicate-formal): New.

	(exception:duplicate-formals): Removed.

	(exception:bad-formals): Adapted to the new way of error
	reporting.

	Adapted tests for 'lambda' to the new way of error reporting.