[lldb] NFC modernize codebase with modernize-use-nullptr

Summary:
NFC = [[ https://llvm.org/docs/Lexicon.html#nfc | Non functional change ]]

This commit is the result of modernizing the LLDB codebase by using
`nullptr` instread of `0` or `NULL`. See
https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-nullptr.html
for more information.

This is the command I ran and I to fix and format the code base:

```
run-clang-tidy.py \
	-header-filter='.*' \
	-checks='-*,modernize-use-nullptr' \
	-fix ~/dev/llvm-project/lldb/.* \
	-format \
	-style LLVM \
	-p ~/llvm-builds/debug-ninja-gcc
```

NOTE: There were also changes to `llvm/utils/unittest` but I did not
include them because I felt that maybe this library shall be updated in
isolation somehow.

NOTE: I know this is a rather large commit but it is a nobrainer in most
parts.

Reviewers: martong, espindola, shafik, #lldb, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: arsenm, jvesely, nhaehnle, hiraditya, JDevlieghere, teemperor, rnkovacs, emaste, kubamracek, nemanjai, ki.stfu, javed.absar, arichardson, kbarton, jrtc27, MaskRay, atanasyan, dexonsmith, arphaman, jfb, jsji, jdoerfert, lldb-commits, llvm-commits

Tags: #lldb, #llvm

Differential Revision: https://reviews.llvm.org/D61847

llvm-svn: 361484

lldb/source/API/SBModule.cpp

@@ -40,8 +40,8 @@ SBModule::SBModule(const SBModuleSpec &module_spec) : m_opaque_sp() {
   LLDB_RECORD_CONSTRUCTOR(SBModule, (const lldb::SBModuleSpec &), module_spec);
 
   ModuleSP module_sp;
-  Status error = ModuleList::GetSharedModule(*module_spec.m_opaque_up,
-                                             module_sp, NULL, NULL, NULL);
+  Status error = ModuleList::GetSharedModule(
+      *module_spec.m_opaque_up, module_sp, nullptr, nullptr, nullptr);
   if (module_sp)
     SetSP(module_sp);
 }
@@ -85,7 +85,7 @@ bool SBModule::IsValid() const {
 SBModule::operator bool() const {
   LLDB_RECORD_METHOD_CONST_NO_ARGS(bool, SBModule, operator bool);
 
-  return m_opaque_sp.get() != NULL;
+  return m_opaque_sp.get() != nullptr;
 }
 
 void SBModule::Clear() {
@@ -159,7 +159,7 @@ bool SBModule::SetRemoteInstallFileSpec(lldb::SBFileSpec &file) {
 const uint8_t *SBModule::GetUUIDBytes() const {
   LLDB_RECORD_METHOD_CONST_NO_ARGS(const uint8_t *, SBModule, GetUUIDBytes);
 
-  const uint8_t *uuid_bytes = NULL;
+  const uint8_t *uuid_bytes = nullptr;
   ModuleSP module_sp(GetSP());
   if (module_sp)
     uuid_bytes = module_sp->GetUUID().GetBytes().data();
@@ -170,8 +170,7 @@ const uint8_t *SBModule::GetUUIDBytes() const {
 const char *SBModule::GetUUIDString() const {
   LLDB_RECORD_METHOD_CONST_NO_ARGS(const char *, SBModule, GetUUIDString);
 
-
-  const char *uuid_cstr = NULL;
+  const char *uuid_cstr = nullptr;
   ModuleSP module_sp(GetSP());
   if (module_sp) {
     // We are going to return a "const char *" value through the public API, so
@@ -185,7 +184,7 @@ const char *SBModule::GetUUIDString() const {
     return uuid_cstr;
   }
 
-  return NULL;
+  return nullptr;
 }
 
 bool SBModule::operator==(const SBModule &rhs) const {
@@ -296,7 +295,7 @@ static Symtab *GetUnifiedSymbolTable(const lldb::ModuleSP &module_sp) {
     if (symbols)
       return symbols->GetSymtab();
   }
-  return NULL;
+  return nullptr;
 }
 
 size_t SBModule::GetNumSymbols() {
@@ -410,7 +409,7 @@ lldb::SBSymbolContextList SBModule::FindFunctions(const char *name,
     const bool symbols_ok = true;
     const bool inlines_ok = true;
     FunctionNameType type = static_cast<FunctionNameType>(name_type_mask);
-    module_sp->FindFunctions(ConstString(name), NULL, type, symbols_ok,
+    module_sp->FindFunctions(ConstString(name), nullptr, type, symbols_ok,
                              inlines_ok, append, *sb_sc_list);
   }
   return LLDB_RECORD_RESULT(sb_sc_list);
@@ -427,7 +426,7 @@ SBValueList SBModule::FindGlobalVariables(SBTarget &target, const char *name,
   if (name && module_sp) {
     VariableList variable_list;
     const uint32_t match_count = module_sp->FindGlobalVariables(
-        ConstString(name), NULL, max_matches, variable_list);
+        ConstString(name), nullptr, max_matches, variable_list);
 
     if (match_count > 0) {
       for (uint32_t i = 0; i < match_count; ++i) {
@@ -558,7 +557,7 @@ lldb::SBTypeList SBModule::GetTypes(uint32_t type_mask) {
 
   TypeClass type_class = static_cast<TypeClass>(type_mask);
   TypeList type_list;
-  vendor->GetTypes(NULL, type_class, type_list);
+  vendor->GetTypes(nullptr, type_class, type_list);
   sb_type_list.m_opaque_up->Append(type_list);
   return LLDB_RECORD_RESULT(sb_type_list);
 }
@@ -606,7 +605,7 @@ const char *SBModule::GetTriple() {
     ConstString const_triple(triple.c_str());
     return const_triple.GetCString();
   }
-  return NULL;
+  return nullptr;
 }
 
 uint32_t SBModule::GetAddressByteSize() {