debug.adb: Update documentation.

debug.adb: Update documentation.

2015-05-22  Robert Dewar  <dewar@adacore.com>

	* debug.adb: Update documentation.
	* einfo.ads, einfo.adb (Needs_Typedef): New flag
	* exp_unst.adb (Unnest_Subprogram): Mark AREC types as needing
	typedef's in C.
	* frontend.adb: Update comments.
	* gnat1drv.adb (Adjust_Global_Switches): Set all needed flags
	for -gnatd.V
	* opt.ads (Generate_C_Code): New switch.
	* osint-c.adb (Write_C_File_Info): Removed, not used
	(Write_H_File_Info): Removed, not used
	* osint-c.ads (Write_C_File_Info): Removed, not used
	(Write_H_File_Info): Removed, not used
	* osint.ads (Write_Info): Minor comment updates.
	(Output_FD): Moved from private part to public part of spec.
	* sem.adb (Semantics): Force expansion on if in Generate_C_Code
	mode.
	* atree.ads: minor typo in comment.
	* sem_prag.adb (Process_Atomic_Independent_Shared_Volatile):
	Do not allow VFA on composite object with aliased component.

From-SVN: r223546