Folding exponent can make the compiler crash

[trocher]

Version Information

• vyper Version (output of vyper --version OR linkable commit hash vyperlang/vyper@commitish): 0.4.0rc3+commit.6d4c09cd

Issue description

When having x ** y folded, if x == 0 or x == 1, the compiler will crash.

See:

vyper/vyper/ast/nodes.py

Lines 1105 to 1106 in 6d4c09c

	if right > math.log(decimal.Decimal(2**257)) / math.log(decimal.Decimal(left)):
	raise InvalidLiteral("Out of bounds", self)

POC

@external
def foo()->uint256:
   return 1**2

ZeroDivisionError: float division by zero

@external
def foo()->uint256:
   return 0**2

ValueError: math domain error