// the parsing of the AST, only the conversion of the AST
	// to a string.
	LLVMStyle
)

// maxLengthShift is how we shift the MaxLength value.
const maxLengthShift = 16

// maxLengthMask is a mask for the maxLength value.
const maxLengthMask = 0x1f << maxLengthShift

// MaxLength returns an Option that limits the maximum length of a
// demangled string. The maximum length is expressed as a power of 2,

// generic.rules changes ANDs of high-part/low-part masks into a couple of shifts,
// for instance:
//    x & 0xFFFF0000 -> (x >> 16) << 16
//    x & 0x80000000 -> (x >> 31) << 31
//
// In case the mask is just one bit (like second example above), it conflicts
// with the above rules to detect bit-testing / bit-clearing of first/last bit.
// We thus special-case them, by detecting the shift patterns.