DiSL: AsmHelper: made return types of insn factories more specific
DiSL: AsmHelper: split getClassType() into getTypeConstOperand(), isTypeConstLoadInsn(), and getOwnerBoxedType() (the code in the last does not seem to be used)
DiSL: AsmHelper: added several utility and factory methods
DiSL: AsmHelper: cleaned up the code of many methods
DiSL: Updated Code, SnippetCode, WeavingCode, CodeMerger, and ProcCode to use cloneCode() from ClonedCode