2002-04-30 Miguel de Icaza <miguel@ximian.com>

2002-04-30  Miguel de Icaza  <miguel@ximian.com>

	* assign.cs (CompoundAssign): A new class used as a "flag" that
	the assignment actually is happening as part of a compound
	assignment operator.

	During compound assignment, a few new rules exist to enable things
	like:

	byte b |= 1 + 2

	From the spec:

	x op= y can be evaluated as x = (T) (x op y) (ie, an explicit cast
	to the type of x) if y is implicitly convertible to the type of x,
	and the operator is a builtin operator and the return type of the
	operator is explicitly convertible to the type of x.

	* rootcontext.cs: Reset warning level to 2.  4 catches various
	"interesting" features in mcs, we must clean this up at some
	point, but currently am trying to kill other bugs ;-)

svn path=/trunk/mcs/; revision=4179