Also removed the default argument value of `skip_nop` for function
`SinglePassRunAndCheck()` and `SinglePassRunAndDisassemble()`. This is
required to support variadic arguments.
AssemblyBuilder contains boilplates.
Adds OpName instructions for all added defining instructions.
Adds OpDecorate SpecId for all spec constants added with OpSpecConstant,
OpSpecConstantTrue and OpSpecConstantFalse instructions.