Update thunktemplates.S (#100066)

Author: filipnavara

src/coreclr/vm/arm/thunktemplates.S

@@ -11,7 +11,7 @@
 
 PAGE_SIZE = 4096
 
-#define DATA_SLOT(stub, field) stub##Code + PAGE_SIZE + stub##Data__##field
+#define DATA_SLOT(stub, field) . - (. - stub##Code) + PAGE_SIZE + stub##Data__##field
 
     LEAF_ENTRY StubPrecodeCode
         ldr r12, DATA_SLOT(StubPrecode, MethodDesc)