[LoongArch64] just skip the array type. (#86290)

The `struct {int array[1]; float field_2;}` which the array field is only one element,
just skip it although it can be passed by registers one integer and one float-register.
Details see github #62885 (comment)

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

src/coreclr/vm/methodtable.cpp

@@ -3443,6 +3443,11 @@ int MethodTable::GetLoongArch64PassStructInRegisterFlags(CORINFO_CLASS_HANDLE cl
                         size = STRUCT_FIRST_FIELD_SIZE_IS8;
                     }
                 }
+                else if (fieldType == ELEMENT_TYPE_CLASS)
+                {
+                    size = STRUCT_NO_FLOAT_FIELD;
+                    goto _End_arg;
+                }
                 else if (pFieldStart[0].GetSize() == 8)
                 {
                     size = STRUCT_FIRST_FIELD_SIZE_IS8;
@@ -3534,6 +3539,11 @@ int MethodTable::GetLoongArch64PassStructInRegisterFlags(CORINFO_CLASS_HANDLE cl
                         size |= STRUCT_SECOND_FIELD_SIZE_IS8;
                     }
                 }
+                else if (fieldType == ELEMENT_TYPE_CLASS)
+                {
+                    size = STRUCT_NO_FLOAT_FIELD;
+                    goto _End_arg;
+                }
                 else if ((size & STRUCT_FLOAT_FIELD_FIRST) == 0)
                 {
                     size = STRUCT_NO_FLOAT_FIELD;