Incorrect error messages while parsing (non-existent) logical operators `or`, `and`, and `xor` about sdk

[eernstg]

Looks like this is working as intended: The first occurrence of or has operands of type int, hence | could be used; the second occurrence has operands of type bool, hence || could be used. It is true that | is defined for the type bool today, but the vastly most common case is probably that a developer who writes or between two boolean expressions would want to use || rather than |.

[tatumizer]

"is written" should be written as "should be written" or "must be written".
"Is written", as written in the dart error message, doesn't have the intended modality.
The issue is small and rare, and I might have been the only user who has ever seen this message though :-)