Fix compile error in coreclr/vm/methodtable.cpp GetMethodDataHelper

  $runtime/src/coreclr/vm/methodtable.cpp: In static member function 'static MethodTable::MethodData* MethodTable::GetMethodDataHelper(MethodTable*, MethodTable*, MethodDataComputeOptions)':
  $runtime/src/coreclr/vm/methodtable.cpp:7130:52: error: 'static void MethodTable::MethodDataInterface::operator delete(void*)' called on pointer returned from a mismatched allocation function [-Werror=mismatched-new-delete]
   7130 |             pData = new MethodDataInterface(pMTDecl);
        |                                                    ^
  $runtime/src/coreclr/vm/methodtable.cpp:7130:52: note: returned from 'void* operator new(std::size_t)'
   7130 |             pData = new MethodDataInterface(pMTDecl);
        |                                                    ^

Author: gwr

src/coreclr/vm/methodtable.cpp

@@ -7127,7 +7127,7 @@ MethodTable::MethodData *MethodTable::GetMethodDataHelper(MethodTable *pMTDecl,
     // If we get here, there are no entries in the cache.
     if (pMTDecl == pMTImpl) {
         if (pMTDecl->IsInterface()) {
-            pData = new MethodDataInterface(pMTDecl);
+            pData = new (pMTDecl) MethodDataInterface(pMTDecl);
         }
         else {
             MethodDataHolder h(FindParentMethodDataHelper(pMTDecl));