[LLDB] Make 'process load' take remote os path delimiter into account

Currently, if we execute 'process load' with remote debugging,
it uses host's path delimiter to lookup files on target machine.
If we run remote debugging of Linux target on Windows and execute
'process load C:\foo\a.so', lldb-server tries to load \foo\a.so
instead of /foo/a.so.

It affects several API tests.

This commit fixes that error. Also, it contains minor fixes for
TestLoadUnload.py for testing on Windows host and Linux target.

lldb/source/Commands/CommandObjectProcess.cpp

@@ -950,11 +950,13 @@ class CommandObjectProcessLoad : public CommandObjectParsed {
                           ExecutionContext *execution_context) override {
       Status error;
       const int short_option = m_getopt_table[option_idx].val;
+      ArchSpec arch =
+          execution_context->GetProcessPtr()->GetSystemArchitecture();
       switch (short_option) {
       case 'i':
         do_install = true;
         if (!option_arg.empty())
-          install_path.SetFile(option_arg, FileSpec::Style::native);
+          install_path.SetFile(option_arg, arch.GetTriple());
         break;
       default:
         llvm_unreachable("Unimplemented option");

lldb/test/API/functionalities/load_unload/TestLoadUnload.py

@@ -62,7 +62,7 @@ def copy_shlibs_to_remote(self, hidden_dir=False):
             for f in shlibs:
                 err = lldb.remote_platform.Put(
                     lldb.SBFileSpec(self.getBuildArtifact(f)),
-                    lldb.SBFileSpec(os.path.join(wd, f)),
+                    lldb.SBFileSpec(lldbutil.join_remote_paths(wd, f)),
                 )
                 if err.Fail():
                     raise RuntimeError(
@@ -71,7 +71,7 @@ def copy_shlibs_to_remote(self, hidden_dir=False):
             if hidden_dir:
                 shlib = "libloadunload_d." + ext
                 hidden_dir = os.path.join(wd, "hidden")
-                hidden_file = os.path.join(hidden_dir, shlib)
+                hidden_file = lldbutil.join_remote_paths(hidden_dir, shlib)
                 err = lldb.remote_platform.MakeDirectory(hidden_dir)
                 if err.Fail():
                     raise RuntimeError(
@@ -405,8 +405,11 @@ def run_step_over_load(self):
 
     # We can't find a breakpoint location for d_init before launching because
     # executable dependencies are resolved relative to the debuggers PWD. Bug?
+    # The remote lldb server resolves the executable dependencies correctly.
     @expectedFailureAll(
-        oslist=["freebsd", "linux", "netbsd"], triple=no_match("aarch64-.*-android")
+        oslist=["freebsd", "linux", "netbsd"],
+        triple=no_match("aarch64-.*-android"),
+        remote=False,
     )
     @expectedFailureAll(oslist=["windows"], archs=["aarch64"])
     def test_static_init_during_load(self):