Rollup merge of #139677 - jchecahi:profiler-builtin-rtlib-path-fix, r=kobzol

Fix profiler_builtins build script to handle full path to profiler lib

LLVM_PROFILER_RT_LIB may be set to an absolute path (e.g., in Fedora builds), but `-l` expects a library name, not a path. After #138273, this caused builds to fail with a "could not find native static library" error.

This patch updates the build script to split the path into directory and filename, using `cargo::rustc-link-search` for the directory and `cargo::rustc-link-lib=+verbatim` for the file. This allows profiler_builtins to correctly link the static library even when an absolute path is provided.

Author: ChrisDenton