C++20模块文件复用

[24bit-xjkp]

以这个示例工程为例，xmake会为mod和mod2两个目标各编译一次std模块，尽管它们的配置完全相同，编译日志如下：

xmake f --toolchain=clang --runtimes=c++_shared -c                                          
checking for platform ... linux
checking for architecture ... x86_64

xmake build -r                                 
[  2%]: <mod> generating.module.deps src/my_module.cpp
[  2%]: <mod> generating.module.deps src/my_module.mpp
[  2%]: <mod> generating.module.deps /home/luo/Toolchains/x86_64-linux-gnu-clang22/share/libc++/v1/std.cppm
[  2%]: <mod> generating.module.deps /home/luo/Toolchains/x86_64-linux-gnu-clang22/share/libc++/v1/std.compat.cppm
[  2%]: <mod2> generating.module.deps src/my_module.mpp
[  2%]: <mod2> generating.module.deps src/my_module.cpp
[  2%]: <mod2> generating.module.deps /home/luo/Toolchains/x86_64-linux-gnu-clang22/share/libc++/v1/std.cppm
[  2%]: <mod2> generating.module.deps /home/luo/Toolchains/x86_64-linux-gnu-clang22/share/libc++/v1/std.compat.cppm
[ 14%]: <mod> compiling.module.bmi.release std
[ 14%]: <mod2> compiling.module.bmi.release std
[ 18%]: <mod> compiling.module.bmi.release my_module
[ 21%]: compiling.release /home/luo/Toolchains/x86_64-linux-gnu-clang22/share/libc++/v1/std.cppm
[ 25%]: compiling.release src/my_module.mpp
[ 32%]: compiling.release src/my_module.cpp
[ 36%]: <mod2> compiling.module.bmi.release my_module
[ 40%]: compiling.release /home/luo/Toolchains/x86_64-linux-gnu-clang22/share/libc++/v1/std.cppm
[ 43%]: compiling.release src/my_module.mpp
[ 51%]: compiling.release src/my_module.cpp
[ 58%]: linking.release libmod.a
[ 80%]: linking.release libmod2.a
[100%]: build ok, spent 3.909s

xmake版本：v3.0.1+HEAD.3350cc5