[RISCV] Fix the include search path order between sysroot and resource folder (Recommit again)

Resource folder[1] should include before sysroot[2] in general (Linux clang
toolchain, BareMetal clang toolchain, and GCC using that order), and that
prevent sysroot's header file override resource folder's one, this change is
reference from BareMetal::AddClangSystemIncludeArgs@BareMetal.cpp[3].

And also fix the behavior of `-nobuiltininc`.

[1] Include path from resource folder is something like this: `<toolchain-path>/lib/clang/13.0.0/include/`
[2] Include path from sysroot is something like this: `<toolchain-path>/riscv32-unknown-elf/include`
[3] https://github.com/llvm/llvm-project/blob/llvmorg-13.0.1/clang/lib/Driver/ToolChains/BareMetal.cpp#L193

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D119837

The recommit fixes the Windows build failure due to path issue.