re PR ada/30740 (Improper semantics in gnat's compilation of certain expressions involving modular arithmetic)

2008-05-20  Robert Dewar  <dewar@adacore.com>

	PR ada/30740
	* einfo.ads, einfo.adb (Non_Binary_Modulus): Applies to all types and
	subtypes, always False for non-modular types.
	Shared_Var_Assign_Proc (node22) and Shared_Var_Read_Proc (node 15)
	entry nodes have been replaced by Shared_Var_Procs_Instance (node22)
	for Shared_Storage package.
	(Is_RACW_Stub_Type): New entity flag.

	* exp_ch4.adb
	(Expand_N_Op_Expon): Avoid incorrect optimization of a*(2**b) in the
	case where we have a modular type with a non-binary modules.
	Comments reformattings.

	* sem_intr.adb: Simplify code not that Non_Binary_Modulus applies to
	all types.

From-SVN: r135619