Fix test for 32 bit architectures

[ellert]

The size of the struct isdifferent on 32 bit architectures.

[ RUN      ] TypeReflectionTest.GetSizeOfType
/builddir/build/BUILD/root-6.36.00-build/root-6.36.00/interpreter/CppInterOp/unittests/CppInterOp/TypeReflectionTest.cpp:79: Failure
Expected equality of these values:
  Cpp::GetSizeOfType(Cpp::GetVariableType(Decls[4]))
    Which is: 12
  16
[  FAILED  ] TypeReflectionTest.GetSizeOfType (23 ms)

[ RUN      ] ScopeReflectionTest.SizeOf
/builddir/build/BUILD/root-6.36.00-build/root-6.36.00/interpreter/CppInterOp/unittests/CppInterOp/ScopeReflectionTest.cpp:161: Failure
Expected equality of these values:
  Cpp::SizeOf(Decls[7])
    Which is: 12
  (size_t)16
    Which is: 16
[  FAILED  ] ScopeReflectionTest.SizeOf (26 ms)

[guitargeek]

This needs to be reviewed by @Vipul-Cariappa or @aaronj0. Maybe the same change should be applied upstream?

[github-actions]

Test Results

    20 files      20 suites   3d 14h 55m 49s ⏱️
 3 016 tests  3 015 ✅ 0 💤 1 ❌
58 720 runs  58 719 ✅ 0 💤 1 ❌

For more details on these failures, see this check.

Results for commit b5f6092.

♻️ This comment has been updated with latest results.

[aaronj0]

Hi @ellert, thanks again for this nice improvement! This commit has been upstreamed to CppInterOp: compiler-research/CppInterOp#649 and will be pulled into ROOT along with other patches when we move to the latest tag/release. Hence, I will close this PR here and link it when we upgrade.