fix: include bound glibc in compiler environment

[ZheFeng7110]

Summary

• add the exact glibc@<version> payload library directory to Linux compiler child environments
• keep runtime selection explicit; do not scan installed glibc versions
• cover the initial GCC --version probe failing with exit 127 when the directory is absent

Closes #484

Test plan

• git diff --check
• managed GCC 16.1.0 --version succeeds with the bound private glibc plus gcc-runtime directories
• managed GCC 16.1.0 compiles a C++23 source with the bound private glibc, gcc-runtime, and managed binutils
• mcpp test (full self-host build was terminated by an OOM kill while compiling cli.m.cppm)
• CI

[Sunrisepeak]

@ZheFeng7110 这个 /etc/ld.so.preload 的问题 是 libc 侧的问题。可以不用从mcpp侧强行 workaround, 并且从 mcpp 侧无法根本解决这个问题。目前已经从glibc侧解决了这个问题。可以使用最新版本进行尝试

xlings update mcpp -y

# 删除全局缓存目录
rm -rf ~/.mcpp

# 配置镜像(可选)
mcpp self config --mirror CN

然后验证。

[ZheFeng7110]

好的，问题已解决。谢谢