[lldb] Simplify RemoteAwarePlatform::ResolveExecutable

[labath]

Summary

The function had three branches:

• host
• remote-but-not-connected
• remote-and-connected

All three branches overlap to varying degrees. This patch reduces them
to two by merging the two remote branches. The main difference between
the two is (or should be -- the code is fairly convoluted, so it's hard
to be certain) that in the connected case we can try to download the
module from the remote system.

However, there's no need to fork the code for that. We can just proceed
with the normal (connected) search sequence and let the sub-operations
that require a connected host fail.

[labath]

I've added as reviewers everyone who has touched this function recently, in case you have some checks/use-cases you want to try, or can think of other reasons to not do this.

lldb/source/Target/RemoteAwarePlatform.cpp

return m_remote_platform_sp->GetModuleSpec(module_file_spec, arch,
                                                module_spec);
 
   return false;
 }
 
 Status RemoteAwarePlatform::ResolveExecutable(
     const ModuleSpec &module_spec, ModuleSP &exe_module_sp,
     const FileSpecList *module_search_paths_ptr) {
-  Status error;
-  // Nothing special to do here, just use the actual file and architecture
 
-  char exe_path[PATH_MAX];
   ModuleSpec resolved_module_spec(module_spec);
 
-  if (IsHost()) {
-    // If we have "ls" as the exe_file, resolve the executable location based
-    // on the current path variables
-    if (!FileSystem::Instance().Exists(resolved_module_spec.GetFileSpec())) {
-      resolved_module_spec.GetFileSpec().GetPath(exe_path, sizeof(exe_path));
-      resolved_module_spec.GetFileSpec().SetFile(exe_path,
-                                                 FileSpec::Style::native);
-      FileSystem::Instance().Resolve(resolved_module_spec.GetFileSpec());
-    }
+  if (IsRemote())
+    return GetCachedExecutable(resolved_module_spec, exe_module_sp,
+                               module_search_paths_ptr);
+
+
+    char exe_path[PATH_MAX];
 
-    if (!FileSystem::Instance().Exists(resolved_module_spec.GetFileSpec()))
-      FileSystem::Instance().ResolveExecutableLocation(
-          resolved_module_spec.GetFileSpec());
 
-    // Resolve any executable within a bundle on MacOSX
-    Host::ResolveExecutableInBundle(resolved_module_spec.GetFileSpec());
 
-    if (FileSystem::Instance().Exists(resolved_module_spec.GetFileSpec()))
-      error.Clear();
-    else {
-      const uint32_t permissions = FileSystem::Instance().GetPermissions(
-          resolved_module_spec.GetFileSpec());
-      if (permissions && (permissions & eFilePermissionsEveryoneR) == 0)
-        error.SetErrorStringWithFormat(
-            "executable '%s' is not readable",
-            resolved_module_spec.GetFileSpec().GetPath().c_str());
-      else
-        error.SetErrorStringWithFormat(
-            "unable to find executable for '%s'",
-            resolved_module_spec.GetFileSpec().GetPath().c_str());
-    }
-  } else {
-    if (m_remote_platform_sp) {
-      return GetCachedExecutable(resolved_module_spec, exe_module_sp,
-                                 module_search_paths_ptr);
-    }
-
-    // We may connect to a process and use the provided executable (Don't use
-    // local $PATH).
-
-    // Resolve any executable within a bundle on MacOSX
-    Host::ResolveExecutableInBundle(resolved_module_spec.GetFileSpec());
-
-    if (FileSystem::Instance().Exists(resolved_module_spec.GetFileSpec()))
-      error.Clear();
-    else
-      error.SetErrorStringWithFormat("the platform is not currently "
-                                     "connected, and '%s' doesn't exist in "
-                                     "the system root.",
-                                     exe_path);
-  }
+  Status error;
+  if (!FileSystem::Instance().Exists(resolved_module_spec.GetFileSpec())) {
 
   if (error.Success()) {
     if (resolved_module_spec.GetArchitecture().IsValid()) {
       error = ModuleList::GetSharedModule(resolved_module_spec, exe_module_sp,
                                           module_search_paths_ptr, nullptr, nullptr);
       if (error.Fail()) {
         // If we failed, it may be because the vendor and os aren't known. If
   // that is the case, try setting them to the host architecture and give