Merge "Tighter equals/hashCode method checking."

def verify_equals(clazz):

    """Verify that equals() and hashCode() must be overridden together."""

    methods = [ m.name for m in clazz.methods ]

    eq = "equals" in methods

    hc = "hashCode" in methods

    eq = False

    hc = False

    for m in clazz.methods:

        if " static " in m.raw: continue

        if "boolean equals(java.lang.Object)" in m.raw: eq = True

        if "int hashCode()" in m.raw: hc = True

    if eq != hc:

        error(clazz, None, "M8", "Must override both equals and hashCode; missing one")