[fpc-pascal] implementation-part

[Adriaan van Os]

The Freepascal Language Reference (version 3.2.0) states in section 16.2

"As can be seen from the syntax diagram, a unit always consists of a interface and an 
implementation part."

and

"Both the interface part or implementation part can be empty, but the keywords Interface and 
implementation must be specified.

However, this was changed when implementing macpas mode (or at least for the macpas mode) in that 
the implementation part is no longer obligatory. This is useful for units with (only) external 
declarations.

Regards,

Adriaan van Os