yields a typed constant.
</p>

<pre>
uint(iota)               // iota value of type uint
float32(2.718281828)     // 2.718281828 of type float32
complex128(1)            // 1.0 + 0.0i of type complex128
float32(0.49999999)      // 0.5 of type float32
float64(-1e-1000)        // 0.0 of type float64
string('x')              // "x" of type string
string(0x266c)           // "♬" of type string

	{ir.OBITNOT, types.TINT64}:  ssa.OpCom64,
	{ir.OBITNOT, types.TUINT64}: ssa.OpCom64,

	{ir.OIMAG, types.TCOMPLEX64}:  ssa.OpComplexImag,
	{ir.OIMAG, types.TCOMPLEX128}: ssa.OpComplexImag,
	{ir.OREAL, types.TCOMPLEX64}:  ssa.OpComplexReal,
	{ir.OREAL, types.TCOMPLEX128}: ssa.OpComplexReal,

	{ir.OMUL, types.TINT8}:    ssa.OpMul8,
	{ir.OMUL, types.TUINT8}:   ssa.OpMul8,
	{ir.OMUL, types.TINT16}:   ssa.OpMul16,