[clang] Fix behavior of `__is_trivially_relocatable(volatile int)` (#77092)

Consistent with `__is_trivially_copyable(volatile int) == true` and
`__is_trivially_relocatable(volatile Trivial) == true`,
`__is_trivially_relocatable(volatile int)` should also be `true`.

Fixes https://github.com/llvm/llvm-project/issues/77091

[clang] [test] New tests for __is_trivially_relocatable(cv-qualified
type)