[Ada] Minor tweak to -gnatR output

[Ada] Minor tweak to -gnatR output

This makes sure that the numbers present in the -gnatR output are
printed in decimal format in all cases, since the hexadecimal format is
not compatible with the JSON syntax.

2019-07-23  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* repinfo.adb (List_Component_Layout): Pass Decimal to UI_Write.
	(Write_Val): Likewise.

From-SVN: r273723