139 - solc 0.7.0 Breaking

Solidity v0.7.0 Breaking Semantic Changes - changes where existing code changes its behaviour without the compiler notifying you about it:

Exponentiation and shifts of literals by non-literals (e.g. 1 << x or 2 ** x) will always use either the type uint256 (for non-negative literals) or int256 (for negative literals) to perform the operation.

Previously, the operation was performed in the type of the shift amount / the exponent which can be misleading.