Disable map checks in usm mode, to overcome bug preventing removal of map information when exiting target data environment.

https://ontrack-internal.amd.com/browse/SWDEV-336718

Change-Id: Ie81262cd019cb21031eecd675e12cbb3a1bf7bdb

Author: ronlieb

openmp/libomptarget/include/rtl.h

@@ -140,8 +140,8 @@ struct RTLsTy {
   int64_t RequiresFlags = OMP_REQ_UNDEFINED;
 
   // Set by OMPX_DISABLE_MAPS environment variable.
-  // When active, maps are ignored by the runtime
-  bool NoUSMMapChecks = false;
+  // When active (default state), maps are ignored by the runtime
+  bool NoUSMMapChecks = true;
 
   explicit RTLsTy() = default;
 

openmp/libomptarget/src/device.cpp

@@ -261,15 +261,15 @@ DeviceTy::getTargetPointer(void *HstPtrBegin, void *HstPtrBase, int64_t Size,
     // In addition to the mapping rules above, the close map modifier forces the
     // mapping of the variable to the device.
     if (Size) {
+      // When allocating under unified_shared_memory, amdgpu plugin
+      // can optimize memory access latency by registering allocated
+      // memory as coarse_grain
+      if (HstPtrBegin && RTL->set_coarse_grain_mem_region)
+        RTL->set_coarse_grain_mem_region(HstPtrBegin, Size);
+
       if (!PM->RTLs.NoUSMMapChecks) {
-        // When allocating under unified_shared_memory, amdgpu plugin
-	// can optimize memory access latency by registering allocated
-	// memory as coarse_grain
-	if (HstPtrBegin && RTL->set_coarse_grain_mem_region)
-	  RTL->set_coarse_grain_mem_region(HstPtrBegin, Size);
-
-	// even under unified_shared_memory need to check for correctness of
-	// use of map clauses. device pointer is same as host ptr in this case
+        // even under unified_shared_memory need to check for correctness of
+        // use of map clauses. device pointer is same as host ptr in this case
         Entry =
             HostDataToTargetMap
                 .emplace((uintptr_t)HstPtrBase, (uintptr_t)HstPtrBegin,