checks.adb (Apply_Arithmetic_Overflow_Check): Avoid intermediate overflow if…

checks.adb (Apply_Arithmetic_Overflow_Check): Avoid intermediate overflow if result converted to wider integer type.

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

	* checks.adb (Apply_Arithmetic_Overflow_Check): Avoid intermediate
	overflow if result converted to wider integer type.
	(Apply_Type_Conversion_Checks): Don't emit checks on conversions to
	discriminated types when discriminant checks are suppressed.

From-SVN: r135616