[Ada] Retain Has_Private_View flag for actuals of inlined subprograms

[Ada] Retain Has_Private_View flag for actuals of inlined subprograms

When instantiating a body to inline (either because frontend inlining is
enabled with switch -gnatN or because of inlining-for-proof in GNATprove
mode) we rewrite occurrences of formal parameters into the corresponding
actual parameters. Then we switch type views, so that if the formal had
a full view in the body to inline then the corresponding actual will
have a full view in the particular inlined body.

However, when rewriting occurrences of the formal parameter we were
losing information about whether the formal had a private view.

gcc/ada/

	* inline.adb (Process_Formals): Preserve Has_Private_View flag while
	rewriting formal into actual parameters.