Revert "Apply modernize-use-default to compiler-rt."

This reverts commit r250823.

Replacing at least some of empty
constructors with "= default" variants is a semantical change which we
don't want. E.g. __tsan::ClockBlock contains a union of large arrays,
and it's critical for correctness and performance that we don't memset()
these arrays in the constructor.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@251717 91177308-0d34-0410-b5e6-96231b3b80d8

lib/asan/asan_fake_stack.h

@@ -155,7 +155,7 @@ class FakeStack {
   void ForEachFakeFrame(RangeIteratorCallback callback, void *arg);
 
  private:
-  FakeStack() = default;
+  FakeStack() { }
   static const uptr kFlagsOffset = 4096;  // This is were the flags begin.
   // Must match the number of uses of DEFINE_STACK_MALLOC_FREE_WITH_CLASS_ID
   COMPILER_CHECK(kNumberOfSizeClasses == 11);

lib/msan/msan_allocator.h

@@ -26,7 +26,7 @@ struct MsanThreadLocalMallocStorage {
 
  private:
   // These objects are allocated via mmap() and are zero-initialized.
-  MsanThreadLocalMallocStorage() = default;
+  MsanThreadLocalMallocStorage() {}
 };
 
 } // namespace __msan

lib/sanitizer_common/sanitizer_bitvector.h

@@ -87,7 +87,7 @@ class BasicBitVector {
   // }
   class Iterator {
    public:
-    Iterator() = default;
+    Iterator() { }
     explicit Iterator(const BasicBitVector &bv) : bv_(bv) {}
     bool hasNext() const { return !bv_.empty(); }
     uptr next() { return bv_.getAndClearFirstOne(); }
@@ -273,7 +273,7 @@ class TwoLevelBitVector {
   // }
   class Iterator {
    public:
-    Iterator() = default;
+    Iterator() { }
     explicit Iterator(const TwoLevelBitVector &bv) : bv_(bv), i0_(0), i1_(0) {
       it1_.clear();
       it2_.clear();

lib/tsan/rtl/tsan_clock.h

@@ -33,7 +33,8 @@ struct ClockBlock {
     ClockElem clock[kClockCount];
   };
 
-  ClockBlock() = default;
+  ClockBlock() {
+  }
 };
 
 typedef DenseSlabAlloc<ClockBlock, 1<<16, 1<<10> ClockAlloc;

lib/tsan/rtl/tsan_mutex.cc

@@ -126,8 +126,9 @@ void InitializeMutex() {
 #endif
 }
 
-// Rely on zero initialization because some mutexes can be locked before ctor.
-InternalDeadlockDetector::InternalDeadlockDetector() = default;
+InternalDeadlockDetector::InternalDeadlockDetector() {
+  // Rely on zero initialization because some mutexes can be locked before ctor.
+}
 
 #if SANITIZER_DEBUG && !SANITIZER_GO
 void InternalDeadlockDetector::Lock(MutexType t) {

lib/tsan/rtl/tsan_report.cc

@@ -67,8 +67,9 @@ ReportMop::ReportMop()
     : mset(MBlockReportMutex) {
 }
 
-// FIXME(dvyukov): it must be leaking a lot of memory.
-ReportDesc::~ReportDesc() = default;
+ReportDesc::~ReportDesc() {
+  // FIXME(dvyukov): it must be leaking a lot of memory.
+}
 
 #ifndef SANITIZER_GO
 

lib/tsan/rtl/tsan_rtl_thread.cc

@@ -31,7 +31,8 @@ ThreadContext::ThreadContext(int tid)
 }
 
 #ifndef SANITIZER_GO
-ThreadContext::~ThreadContext() = default;
+ThreadContext::~ThreadContext() {
+}
 #endif
 
 void ThreadContext::OnDead() {

lib/ubsan/ubsan_diag.h

@@ -150,7 +150,7 @@ public:
 
   /// An individual diagnostic message argument.
   struct Arg {
-    Arg() = default;
+    Arg() {}
     Arg(const char *String) : Kind(AK_String), String(String) {}
     Arg(TypeName TN) : Kind(AK_TypeName), String(TN.getName()) {}
     Arg(UIntMax UInt) : Kind(AK_UInt), UInt(UInt) {}