Replace 'ap' with 'up' suffix in variable names. (NFC)

The `ap` suffix is a remnant of lldb's former use of auto pointers,
before they got deprecated. Although all their uses were replaced by
unique pointers, some variables still carried the suffix.

In r353795 I removed another auto_ptr remnant, namely redundant calls to
::get for unique_pointers. Jim justly noted that this is a good
opportunity to clean up the variable names as well.

I went over all the changes to ensure my find-and-replace didn't have
any undesired side-effects. I hope I didn't miss any, but if you end up
at this commit doing a git blame on a weirdly named variable, please
know that the change was unintentional.

llvm-svn: 353912
diff --git a/lldb/source/Target/LanguageRuntime.cpp b/lldb/source/Target/LanguageRuntime.cpp
index 8203c9e..d008006 100644
--- a/lldb/source/Target/LanguageRuntime.cpp
+++ b/lldb/source/Target/LanguageRuntime.cpp
@@ -201,7 +201,7 @@
 
 LanguageRuntime *LanguageRuntime::FindPlugin(Process *process,
                                              lldb::LanguageType language) {
-  std::unique_ptr<LanguageRuntime> language_runtime_ap;
+  std::unique_ptr<LanguageRuntime> language_runtime_up;
   LanguageRuntimeCreateInstance create_callback;
 
   for (uint32_t idx = 0;
@@ -209,10 +209,10 @@
             PluginManager::GetLanguageRuntimeCreateCallbackAtIndex(idx)) !=
        nullptr;
        ++idx) {
-    language_runtime_ap.reset(create_callback(process, language));
+    language_runtime_up.reset(create_callback(process, language));
 
-    if (language_runtime_ap)
-      return language_runtime_ap.release();
+    if (language_runtime_up)
+      return language_runtime_up.release();
   }
 
   return nullptr;