Imgui initial changes & shim (Claude Opus 4.6)

Can now draw ImGui demo.

Dockerfile

@@ -5,9 +5,12 @@ VOLUME ["/code"]
 ENV DEBIAN_FRONTEND=noninteractive
 RUN dpkg --add-architecture i386
 RUN apt-get update && apt-get install -y \
-	curl dos2unix wget git make nasm binutils:i386 xorriso grub-pc-bin && \
+	curl dos2unix wget git make nasm binutils xorriso grub-pc-bin \
+	gcc-multilib g++-multilib && \
 	apt-get clean my room
 
+RUN git clone --depth=1 --recurse-submodules https://github.com/cimgui/cimgui.git /cimgui
+
 SHELL ["/bin/bash", "-c"]
 ARG FPC_VERSION=2.6.4
 RUN curl -sL https://sourceforge.net/projects/freepascal/files/Linux/$FPC_VERSION/fpc-$FPC_VERSION.i386-linux.tar/download | tar -xf - && \