[OpenMP][AMDGPU] Add DynamicLdsSize to AMDGPUImplicitArgsTy(#65325)

Add DynamicLdsSize to AMDGPUImplicitArgsTy struct at offset 120 and fill
the dynamic LDS size before kernel launch.

Author: skc7

openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp

@@ -3203,6 +3203,7 @@ Error AMDGPUKernelTy::launchImpl(GenericDeviceTy &GenericDevice,
     ImplArgs->GroupSizeY = 1;
     ImplArgs->GroupSizeZ = 1;
     ImplArgs->GridDims = 1;
+    ImplArgs->DynamicLdsSize = KernelArgs.DynCGroupMem;
   }
 
   // Push the kernel launch into the stream.

openmp/libomptarget/plugins-nextgen/amdgpu/utils/UtilitiesRTL.h

@@ -45,7 +45,9 @@ struct AMDGPUImplicitArgsTy {
   uint16_t GroupSizeZ;
   uint8_t Unused0[46]; // 46 byte offset.
   uint16_t GridDims;
-  uint8_t Unused1[190]; // 190 byte offset.
+  uint8_t Unused1[54]; // 54 byte offset.
+  uint32_t DynamicLdsSize;
+  uint8_t Unused2[132]; // 132 byte offset.
 };
 
 // Dummy struct for COV4 implicitargs.