Defining macros in proper place will improve header
compatibility.
JIRA issue: CORE-19268
- Move WM_IME_SYSTEM macro in <undocuser.h>
into <imm32_undoc.h>.
- Move IMS_... macros in <immdev.h> into
<imm32_undoc.h>.
- Include <imm32_undoc.h> in base/ctf/msutb.