public MaskedLong shiftLeft(long n) {
		if (n == 0) {
			return this;
		}
		// Zeros, not unknowns, fill the right
		long atright = ~((-1L) << n);
		return fromMaskAndValue((this.msk << n) | atright, this.val << n);
	}
Shift the bits @{code n} positions left

<p>
This implements both a signed and unsigned shift.

@param n the number of positions.
@return the result.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/assembler/sleigh/expr/MaskedLong.java