Cannot create noncontig union type larger than 64 bits.

Cannot create noncontig union type larger than 64 bits.

We only can handle integral types of sizes up to 64 bits.
When we see a complex location description like:

	location             (exprloc)
	[   0] reg0
	[   1] piece 8
	[   3] reg1
	[   4] piece 8

For a type like:

	base_type
	byte_size            (data1) 16
	encoding             (data1) signed (5)
	name                 (strp) "__int128"

We'll have to give up, otherwise we'll try to reconstruct the pieces
into a (non-existing) uint128_t type union.