Run clang-tidy modernize-use-equals-{delete,default} on //courgette

See the bugs and cxx post for justification and details:
https://groups.google.com/a/chromium.org/forum/#!topic/cxx/RkOHzIK6Tq8

This change was done using clang-tidy as described here:
https://chromium.googlesource.com/chromium/src/+/lkcr/docs/clang_tidy.md

In some cases the the tool leaves behind a string of commas where it
replaced a member initializer list
(https://bugs.llvm.org/show_bug.cgi?id=35051). They were cleaned up with:
  git diff --name-only | \
    xargs sed -E -i 's/(^\s*|\)\s*):[ ,]*= default/\1 = default/'

BUG=778959,778957

Change-Id: If5ff4c9b313efb82c9a53d2ea4540c5ef4a9abb0
Reviewed-on: https://chromium-review.googlesource.com/789721
Reviewed-by: Tommi <tommi@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Commit-Queue: Chris Watkins <watk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#520412}

diff --git a/courgette/adjustment_method.cc b/courgette/adjustment_method.cc
index c1b4131a..ad05f141 100644
--- a/courgette/adjustment_method.cc
+++ b/courgette/adjustment_method.cc

@@ -571,7 +571,7 @@
       : prog_(NULL),
         model_(NULL),
         debug_label_index_gen_(0) {}
-  ~GraphAdjuster() {}
+  ~GraphAdjuster() = default;
 
   bool Adjust(const AssemblyProgram& model, AssemblyProgram* program) {
     VLOG(1) << "GraphAdjuster::Adjust";

diff --git a/courgette/adjustment_method_2.cc b/courgette/adjustment_method_2.cc
index 1e60c65f..99c1103 100644
--- a/courgette/adjustment_method_2.cc
+++ b/courgette/adjustment_method_2.cc

@@ -427,7 +427,7 @@
   // VS2005's implementation of std::set<T>::set() requires T to have a copy
   // constructor.
   //   DISALLOW_COPY_AND_ASSIGN(Shingle);
-  void operator=(const Shingle&);  // Disallow assignment only.
+  void operator=(const Shingle&) = delete;  // Disallow assignment only.
 };
 
 std::string ToString(const Shingle* instance) {
@@ -746,7 +746,7 @@
  public:
   typedef std::pair<int, LabelInfo*> ScoreAndLabel;
 
-  VariableQueue() {}
+  VariableQueue() = default;
 
   bool empty() const { return queue_.empty(); }
 
@@ -1225,7 +1225,7 @@
 class Adjuster : public AdjustmentMethod {
  public:
   Adjuster() : prog_(NULL), model_(NULL) {}
-  ~Adjuster() {}
+  ~Adjuster() = default;
 
   bool Adjust(const AssemblyProgram& model, AssemblyProgram* program) {
     VLOG(1) << "Adjuster::Adjust";

diff --git a/courgette/courgette_tool.cc b/courgette/courgette_tool.cc
index 7abcf6e..7079811 100644
--- a/courgette/courgette_tool.cc
+++ b/courgette/courgette_tool.cc

@@ -83,7 +83,7 @@
     if (!buffer_.Initialize(file_name))
       Problem("Can't read %s file.", kind);
   }
-  ~BufferedFileReader() override {}
+  ~BufferedFileReader() override = default;
 
   // courgette::BasicBuffer:
   const uint8_t* data() const override { return buffer_.data(); }

diff --git a/courgette/difference_estimator.cc b/courgette/difference_estimator.cc
index ac9f0d4..099900c 100644
--- a/courgette/difference_estimator.cc
+++ b/courgette/difference_estimator.cc

@@ -78,7 +78,7 @@
   DISALLOW_COPY_AND_ASSIGN(Subject);
 };
 
-DifferenceEstimator::DifferenceEstimator() {}
+DifferenceEstimator::DifferenceEstimator() = default;
 
 DifferenceEstimator::~DifferenceEstimator() {
   for (size_t i = 0;  i < owned_bases_.size();  ++i)

diff --git a/courgette/disassembler.cc b/courgette/disassembler.cc
index e14ff32..28449899 100644
--- a/courgette/disassembler.cc
+++ b/courgette/disassembler.cc

@@ -40,7 +40,7 @@
   end_ = start_ + length_;
 }
 
-Disassembler::~Disassembler() {}
+Disassembler::~Disassembler() = default;
 
 const uint8_t* Disassembler::FileOffsetToPointer(FileOffset file_offset) const {
   CHECK_LE(file_offset, static_cast<FileOffset>(end_ - start_));

diff --git a/courgette/disassembler_elf_32_x86_unittest.cc b/courgette/disassembler_elf_32_x86_unittest.cc
index d6943b5e..eae89eca 100644
--- a/courgette/disassembler_elf_32_x86_unittest.cc
+++ b/courgette/disassembler_elf_32_x86_unittest.cc

@@ -27,7 +27,7 @@
  public:
   TestDisassemblerElf32X86(const uint8_t* start, size_t length)
       : DisassemblerElf32X86(start, length) {}
-  ~TestDisassemblerElf32X86() override {}
+  ~TestDisassemblerElf32X86() override = default;
 
   void TestSectionHeaderFileOffsetOrder() {
     std::vector<FileOffset> file_offsets;

diff --git a/courgette/encoded_program.cc b/courgette/encoded_program.cc
index c502978..c1f82bd 100644
--- a/courgette/encoded_program.cc
+++ b/courgette/encoded_program.cc

@@ -184,8 +184,8 @@
 // Constructor is here rather than in the header. Although the constructor
 // appears to do nothing it is fact quite large because of the implicit calls to
 // field constructors. Ditto for the destructor.
-EncodedProgram::EncodedProgram() {}
-EncodedProgram::~EncodedProgram() {}
+EncodedProgram::EncodedProgram() = default;
+EncodedProgram::~EncodedProgram() = default;
 
 CheckBool EncodedProgram::ImportLabels(
     const LabelManager& abs32_label_manager,

diff --git a/courgette/ensemble.cc b/courgette/ensemble.cc
index 631dd12..263521e 100644
--- a/courgette/ensemble.cc
+++ b/courgette/ensemble.cc

@@ -21,7 +21,7 @@
     : kind_(kind), ensemble_(ensemble), region_(region) {
 }
 
-Element::~Element() {}
+Element::~Element() = default;
 
 std::string Element::Name() const {
   return ensemble_->name() + "("

diff --git a/courgette/label_manager.cc b/courgette/label_manager.cc
index c3846cc..a22a36c 100644
--- a/courgette/label_manager.cc
+++ b/courgette/label_manager.cc

@@ -32,7 +32,7 @@
   VLOG(1) << used << " of " << labels_->size() << " labels pre-assigned.";
 }
 
-LabelManager::SimpleIndexAssigner::~SimpleIndexAssigner() {}
+LabelManager::SimpleIndexAssigner::~SimpleIndexAssigner() = default;
 
 void LabelManager::SimpleIndexAssigner::DoForwardFill() {
   size_t count = 0;
@@ -91,9 +91,9 @@
   VLOG(1) << "  infill " << count;
 }
 
-LabelManager::LabelManager() {}
+LabelManager::LabelManager() = default;
 
-LabelManager::~LabelManager() {}
+LabelManager::~LabelManager() = default;
 
 // static
 int LabelManager::GetLabelIndexBound(const LabelVector& labels) {

diff --git a/courgette/streams.cc b/courgette/streams.cc
index d6bebf9..87819604 100644
--- a/courgette/streams.cc
+++ b/courgette/streams.cc

@@ -230,9 +230,7 @@
     : count_(kMaxStreams) {
 }
 
-SourceStreamSet::~SourceStreamSet() {
-}
-
+SourceStreamSet::~SourceStreamSet() = default;
 
 // Initializes from |source|.
 // The stream set for N streams is serialized as a header
@@ -322,8 +320,7 @@
   : count_(kMaxStreams) {
 }
 
-SinkStreamSet::~SinkStreamSet() {
-}
+SinkStreamSet::~SinkStreamSet() = default;
 
 void SinkStreamSet::Init(size_t stream_index_limit) {
   count_ = stream_index_limit;