Eliminate result loop when not needed

[nilslice]

In transformed IR, we insert a loop to iterate through the result data like so:

qcs-sdk-qir/src/transform/shot_count_block/snapshots/qcs_sdk_qir__transform__shot_count_block__qir__test__can_transpile_program_with__reduction.snap

Lines 29 to 37 in 8ec1774

	body: ; preds = %body, %body_execution
	%0 = phi i64 [ %select, %body ], [ 0, %body_execution ]
	%1 = phi i64 [ %4, %body ], [ 1, %body_execution ]
	%2 = call i1 @get_readout_bit(%ExecutionResult* %7, i64 %1, i64 0)
	%3 = zext i1 %2 to i64
	%select = add i64 %0, %3
	%4 = add nuw nsw i64 %1, 1
	%5 = icmp ult i64 %1, 42
	br i1 %5, label %body, label %body_cleanup

However, in some cases we may not have any classical instructions to interpret the result, such as:

qcs-sdk-qir/src/transform/shot_count_block/snapshots/qcs_sdk_qir__transform__shot_count_block__qir__test__can_transpile_program_with__parametric.snap

Lines 25 to 29 in 8ec1774

	body: ; preds = %body, %body_execution
	%1 = phi i64 [ %2, %body ], [ 1, %body_execution ]
	%2 = add nuw nsw i64 %1, 1
	%3 = icmp ult i64 %1, 1000
	br i1 %3, label %body, label %body_cleanup

In the latter case it would make sense to remove the loop, even though the program itself is not really useful.