ada: Ignore accessibility actuals in expression pretty-printer

ada: Ignore accessibility actuals in expression pretty-printer

Extra actual parameters for accessibility checks are confusing for the
expression pretty-printer that is used by CodePeer. It seems that nodes
created for the accessibility checks should use the Sloc of the source
expression of accessibility checks, not the target. However, this is
problematic to achieve with the current implementation of accessibility
checks, so with this patch we will simply ignore the accessibility
actuals when computing Slocs for expression pretty-printing.

gcc/ada/

	* errout.adb (First_And_Last_Nodes): Ignore accessibility parameters.