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/ThreadPlanStepInRange.cpp b/lldb/source/Target/ThreadPlanStepInRange.cpp
index 98387b9..6e8fc98 100644
--- a/lldb/source/Target/ThreadPlanStepInRange.cpp
+++ b/lldb/source/Target/ThreadPlanStepInRange.cpp
@@ -314,10 +314,10 @@
 
 void ThreadPlanStepInRange::SetAvoidRegexp(const char *name) {
   auto name_ref = llvm::StringRef::withNullAsEmpty(name);
-  if (!m_avoid_regexp_ap)
-    m_avoid_regexp_ap.reset(new RegularExpression(name_ref));
+  if (!m_avoid_regexp_up)
+    m_avoid_regexp_up.reset(new RegularExpression(name_ref));
 
-  m_avoid_regexp_ap->Compile(name_ref);
+  m_avoid_regexp_up->Compile(name_ref);
 }
 
 void ThreadPlanStepInRange::SetDefaultFlagValue(uint32_t new_value) {
@@ -350,7 +350,7 @@
   if (libraries_say_avoid)
     return true;
 
-  const RegularExpression *avoid_regexp_to_use = m_avoid_regexp_ap.get();
+  const RegularExpression *avoid_regexp_to_use = m_avoid_regexp_up.get();
   if (avoid_regexp_to_use == nullptr)
     avoid_regexp_to_use = GetThread().GetSymbolsToAvoidRegexp();