RFR: C2: fix call with __Value arguments

[Roland Westrelin]

http://cr.openjdk.java.net/~roland/valhalla/__Value_args_cast/webrev.00/

When inlining a method handler linker call, an argument at the call site
can be __Value and the inlined method can be a specific value type. In
that case, we have to create a ValueTypeNode from the value type
reference. I suppose if we hit the opposite situation (call site's
signature uses a specific value type, callee uses __Value) we need a
reference to the value and have to store it to memory. This mirrors what
happens without value types where C2 casts arguments.

Roland.