Use clang for windows host modules

Bug: http://b/69933068

- Remove GCC's intrinsic header path so Clang's headers get included.
- Add '-B' with GCC's binary directory so Clang detects the linker.
- Bug: http://b/109759970 - Pass '--allow-multiple-definition' linker
flag to deal with ld.bfd's inability to handle Clang-generated section
names is fixed.
- Bug: http://b/110800681 - lld cannot link Android's Windows modules
yet

Test: m native-host-cross and run adb_test.exe under wine.

Change-Id: I9be9cfc34a47cbeee04024438dea214305112eaa