Description

As the title says, this PR fixes issues with fractional values in filesize and duration literal values. E.g., 0.5wk is now reported as 3day 12hr instead of 3day.

Fixes #12858, fixes #10612, and fixes #9892.

Implementation wise, this splits the Unit type into FilesizeUnit and DurationType. These types have a few helpful methods and are now used a few other places besides the parser. Additionally, this PR adds the Expr::Filesize and Expr::Duration cases to replace the existing Expr::ValueWithUnit.

User-Facing Changes

Breaking changes:

• Filesizes and durations now follow the same rules as float parsing. E.g., -.0GiB used to not parse as a filesize even though -.0 is parsed as a valid float.
• Filesize and duration literals that are out of the range of an i64 number of bytes or nanos now trigger a parser error.
• Fixed the precision issues with filesize and duration literals. Although this is a bug fix, it is still technically breaking since it changes the values of existing code.
• format filesize now errors on an invalid filsize unit instead of silently continuing.

Current (Known) Limitations

• The whole number part of filesize or duration cannot be outside the range of an i64 even if the exponent is negative. E.g., 9223372036854775808e-1B will give a parser error.
• The value of 10^abs(exponent) must not be larger then i64::MAX, otherwise an error is reported. The means that the only valid exponents are in the range [-18, +18].