[Ada] Fix regression of ACATS c46032a with CCG back end

[Ada] Fix regression of ACATS c46032a with CCG back end

2018-05-28  Javier Miranda  <miranda@adacore.com>

gcc/ada/

	* exp_ch4.adb (Real_Range_Check): Add a temporary to store the integer
	value when converting a float value to a fixed-point value. This is
	required for CCG because it handles fixed-point types by means of
	unsigned integer type variables. The range check is now performed using
	the integer value stored in this temporary.

From-SVN: r260837