Remove to_abs_path

This function is not necessary.

I don't know how it could leak memory, but it was reported
that it does in #1355.

lib/common.h

@@ -796,7 +796,6 @@ std::filesystem::path filepath(const auto &path) {
 
 std::string get_realpath(std::string_view path);
 std::string path_clean(std::string_view path);
-std::filesystem::path to_abs_path(std::filesystem::path path);
 
 //
 // demangle.cc

lib/filepath.cc

@@ -28,12 +28,6 @@ std::string path_clean(std::string_view path) {
   return filepath(path).lexically_normal().string();
 }
 
-std::filesystem::path to_abs_path(std::filesystem::path path) {
-  if (path.is_absolute())
-    return path.lexically_normal();
-  return (std::filesystem::current_path() / path).lexically_normal();
-}
-
 // Returns the path of the mold executable itself
 std::string get_self_path() {
 #if __APPLE__ || _WIN32

src/linker-script.cc

@@ -125,8 +125,7 @@ Script<E>::read_output_format(std::span<std::string_view> tok) {
 
 template <typename E>
 static bool is_in_sysroot(Context<E> &ctx, std::string path) {
-  std::filesystem::path sysroot = to_abs_path(ctx.arg.sysroot);
-  std::string rel = to_abs_path(path).lexically_relative(sysroot).string();
+  std::string rel = std::filesystem::relative(path, ctx.arg.sysroot).string();
   return rel != "." && !rel.starts_with("../");
 }
 

src/passes.cc

@@ -1003,7 +1003,8 @@ void write_repro_file(Context<E> &ctx) {
       // We reopen a file because we may have modified the contents of mf
       // in memory, which is mapped with PROT_WRITE and MAP_PRIVATE.
       MappedFile *mf2 = must_open_file(ctx, mf->name);
-      tar->append(to_abs_path(mf->name).string(), mf2->get_contents());
+      tar->append(std::filesystem::absolute(mf->name).string(),
+                  mf2->get_contents());
       mf2->unmap();
     }
   }