[libomptarget] Initialize reference parameter IsNew within Device::getOrAllocTgtPtr

[ronlieb]

Summary

The two locals IsNew and Pointer_IsNew were uninitialized at declaration, and then passed by
reference to Device.getOrAllocTgtPtr which in turn did not assign on all
paths within the function. This resulted in occasional runtime failures in one application.
 Device::getOrAllocTgtPtr will now initialize IsNew to false on entry to function.

[grokos]

I think it would look better if we initialized those variables inside Device::getOrAllocTgtPtr - the caller should not assume any default value. That's also what happens in target_data_end with the IsLast variable, it is initialized inside Device::getTgtPtrBegin.

[ronlieb]

Modified patch to assign to IsNew on entry to Device::getOrAllocTgtPtr

[grokos]

LGTM.

openmp/libomptarget/src/device.cpp

 // Increment the reference counter.
 // If NULL is returned, then either data allocation failed or the user tried
 // to do an illegal mapping.
 void *DeviceTy::getOrAllocTgtPtr(void *HstPtrBegin, void *HstPtrBase,
     int64_t Size, bool &IsNew, bool &IsHostPtr, bool IsImplicit,
     bool UpdateRefCount, bool HasCloseModifier) {
   void *rc = NULL;
   IsHostPtr = false;
+  IsNew = false;
   DataMapMtx.lock();
   LookupResult lr = lookupMapping(HstPtrBegin, Size);
 
   // Check if the pointer is contained.
   // If a variable is mapped to the device manually by the user - which would
   // lead to the IsContained flag to be true - then we must ensure that the
   // device address is returned even under unified memory conditions.
   if (lr.Flags.IsContained ||