Version 3.0, use ints, drop bit 64

Release Notes - v3.0.0

Changed

• Numeric BinaryFlags APIs now accept int values only.
• Passing float values to numeric mask/flag methods now raises TypeError for strict_types=1 callers.
• Non-strict callers should still cast or validate external values before calling the API because PHP scalar coercion can convert float to int at the call boundary.
• The numeric iterator and JSON serialization contracts are now documented as int-based.

Removed

• Bits::BIT_64.
• The v2.x float-normalization/deprecation path in Traits\InteractsWithNumericFlags.

BIT_64 Notice

Bits::BIT_64 was removed because PHP numbers for bitwise flags are signed. The 64th bit is the sign bit, so it cannot be used reliably as a normal flag.

Using integer-compatible bits avoids these issues.