Fixes to OpenMP examples

Pragma_Examples/OpenMP/C/3_vecadd/README.md

@@ -46,3 +46,16 @@ Version with simple mapping clauses, set ```export HSA_XNACK=0``` to observe beh
 Build and run like above.
 Move data only were necessary a structured data region is used here, set ```export HSA_XNACK=0``` to observe behaviour similar to discrete GPUs
 
+#### 4) with unified shared memory and asynchronous execution
+```
+4_vecadd_async_usm
+```
+Build and run like above.
+Unified memory version with asynchronous OpenMP kernel calls. Don't forget to set ```export HSA_XNACK=1```.
+
+#### 5) with map clauses and asynchronous execution
+```
+5_vecadd_async
+```
+Build and run like above.
+Version with a `target enter data` map clause directive and asynchronous OpenMP kernel calls. Set ```export HSA_XNACK=0``` to observe behaviour similar to discrete GPUs.

Pragma_Examples/OpenMP/C/4_reduction_scalars/1_reduction_scalars/reduction_scalar.c

@@ -8,7 +8,7 @@ int main(int argc, char *argv[]){
    double ce1=0.0;
    double ce2=0.0;
 
-   #pragma target teams distribute parallel do reduction(+:ce1,ce2)
+   #pragma omp target teams distribute parallel for reduction(+:ce1,ce2)
    for (int j = 0; j< 1000; j++){
       ce1 += 1.0;
       ce2 += 1.0;

Pragma_Examples/OpenMP/C/5_device_routines/1_device_routine/1_device_routine_usm/compute.c

@@ -1,4 +1,4 @@
-#pragma requires unified_shared_memory
+#pragma omp requires unified_shared_memory
 #pragma omp declare target
 void compute(double *x){
    *x = 1.0;

Pragma_Examples/OpenMP/C/5_device_routines/1_device_routine/2_device_routine_map/compute.c

@@ -2,3 +2,4 @@
 void compute(double *x){
    *x = 1.0;
 }
+#pragma omp end declare target

Pragma_Examples/OpenMP/C/6_reduction_array/1_reduction_array/reduction_array.c

@@ -7,7 +7,7 @@
 
 int main(int argc, char *argv[]){
    double ce[2]={0.0, 0.0};
-#pragma target teams distribute parallel do simd reduction(+:ce1[0:2])
+#pragma omp target teams distribute parallel for simd reduction(+:ce[0:2])
    for (int j = 0; j< 1000; j++){
       ce[0] += 1.0;
       ce[1] += 1.0;