MinGW support IME

[actboy168]

MingGW disabled IME support, because #738. I don't think MinGW can't use imm.h/imm32.lib.

I want MinGW to enable IME support, only by modifying imgui.cpp.

Can you add a macro IMGUI_ENABLE_WIN32_DEFAULT_IME_FUNCTIONS to enable IME support?

[ocornut]

Please design and submit the PR that could make it work with MinGW. I don't know how MinGW works and how Microsoft IME api can be used with it.

[actboy168]

I think it only needs to remove !defined(__GNUC__) and add ldflag -limm32 to the link.

imgui/imgui.cpp

Line 9699 in cb7ba60

#if defined(_WIN32) && !defined(__GNUC__) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS)

[ocornut]

You just said above "I don't think MinGW can't use imm.h/imm32.lib."

[actboy168]

Eh, I mean MinGW can use imm.h / imm32.lib.

[ocornut]

@actboy168 I apologies it took me so long to review this. A few days ago I was setting up some better mingw build script here and looked at this (previously was mostly running mingw builds without backends). You were absolutely right. I merged the fix here edf135c
Thank you again!

[ocornut]

I pushed 30d164e to undo the change made in 1.82 to enable IME support by default with non-Visual Studio compilers, since in master this is part of the core library rather than the win32 backend it seems reasonable to require explicit enable.
Non Visual Studio users who want IME support in their app need to compile with #define IMGUI_ENABLE_WIN32_DEFAULT_IME_FUNCTIONS.