Remove as_list/as_iterable usage from go_path (#4059)

**What type of PR is this?**
Starlark cleanup

**What does this PR do? Why is it needed?**
These methods obscure the types of vars and are slower than just calling
the underlying function

**Which issues(s) does this PR fix?**

Fixes #

**Other notes for review**

Author: dzbarsky

go/private/tools/path.bzl

@@ -16,11 +16,6 @@ load(
     "@bazel_skylib//lib:paths.bzl",
     "paths",
 )
-load(
-    "//go/private:common.bzl",
-    "as_iterable",
-    "as_list",
-)
 load(
     "//go/private:providers.bzl",
     "GoArchive",
@@ -50,16 +45,16 @@ def _go_path_impl(ctx):
     # Collect sources and data files from archives. Merge archives into packages.
     pkg_map = {}  # map from package path to structs
     for mode, archives in mode_to_archive.items():
-        for archive in as_iterable(archives):
+        for archive in archives.to_list():
             importpath, pkgpath = effective_importpath_pkgpath(archive)
             if importpath == "":
                 continue  # synthetic archive or inferred location
             pkg = struct(
                 importpath = importpath,
                 dir = "src/" + pkgpath,
-                srcs = as_list(archive.srcs),
+                srcs = list(archive.srcs),
                 runfiles = archive.runfiles,
-                embedsrcs = as_list(archive._embedsrcs),
+                embedsrcs = list(archive._embedsrcs),
                 pkgs = {mode: archive.file},
             )
             if pkgpath in pkg_map: