Wildcard matching for deps adds circular dependencies

>>> import loopy as lp
>>> knl = lp.make_kernel("{[i]: 0 <= i < 10}",
... """
... a = 1 {id=insn0}
... b = 2 {id=insn1, dep=insn*}
... """)
>>> knl.instructions[1].depends_on
frozenset({'insn0', 'insn1'})

Related: found while addressing #110 (closed)