Inline asm exprs should be RvalueStmtExpr.
Actually pass inline asm operands around.
Properly handle input operands for inline asm.
Initial support for output operands in asm.
Implicitly use addr_of for output operands in asm.
Actually use no or multiple operands properly.
Tidy.
Don't use by_val for passing asm operands.
Fix type_use for inline asm.