Should allow ILL_H15_SAM to execute on GPU/OpenACC

Author: willend

mcstas-comps/examples/ILL/ILL_H15_SAM/ILL_H15_SAM.instr

@@ -78,6 +78,7 @@ DECLARE %{
 	double sT3=16.7 ,sI3=3.0423e+12;
 	/* Some instrument params */
 	int ssshape=1;				/* Code for sample slit shape: default = rectangular (1), set to circular (2) if ssh <= 0 */
+        #pragma acc declare create(ssshape)
 	double rbs=2.75e-2;			/* Beamstop radius */
 	double lcoll;				/* Effective collimation length */
 	double sow;					/* Source effective width */
@@ -109,6 +110,7 @@ INITIALIZE %{
 		ssshape=2;
 		maxvdiv=maxhdiv;
 	}
+        #pragma acc update device(ssshape)
 
 	tthmin=atan(rbs/lsd);
 	tthmax=atan(sqrt(2)*0.32/lsd);