swift234

teach IRGenFunction::emitIgnored to handle expressions of module and metattype type.
Teach Expr::getSemanticsProvidingExpr to look through DotSyntaxBaseIgnoredExpr.
Start generating DotSyntaxBaseIgnoredExpr for all dot syntax exprs where the base is
ignored (e.g. "Builtin.mul_i32"), which preserves a lot more source location information
and is general goodness for the AST.


Swift SVN r1232