Remove unnecessary `explicit` qualifiers on constructors.

Change-Id: Id12e392ad50f66a6e2251a68662b7959315dc567
diff --git a/compiler/utils/arm/assembler_arm.h b/compiler/utils/arm/assembler_arm.h
index 5d85d11..ef60fef 100644
--- a/compiler/utils/arm/assembler_arm.h
+++ b/compiler/utils/arm/assembler_arm.h
@@ -888,7 +888,7 @@
 // Slowpath entered when Thread::Current()->_exception is non-null
 class ArmExceptionSlowPath FINAL : public SlowPath {
  public:
-  explicit ArmExceptionSlowPath(ArmManagedRegister scratch, size_t stack_adjust)
+  ArmExceptionSlowPath(ArmManagedRegister scratch, size_t stack_adjust)
       : scratch_(scratch), stack_adjust_(stack_adjust) {
   }
   void Emit(Assembler *sp_asm) OVERRIDE;
diff --git a/compiler/utils/arm64/assembler_arm64.h b/compiler/utils/arm64/assembler_arm64.h
index 05882a3..8e85fe9 100644
--- a/compiler/utils/arm64/assembler_arm64.h
+++ b/compiler/utils/arm64/assembler_arm64.h
@@ -254,7 +254,7 @@
 
 class Arm64Exception {
  private:
-  explicit Arm64Exception(Arm64ManagedRegister scratch, size_t stack_adjust)
+  Arm64Exception(Arm64ManagedRegister scratch, size_t stack_adjust)
       : scratch_(scratch), stack_adjust_(stack_adjust) {
     }
 
diff --git a/compiler/utils/dedupe_set.h b/compiler/utils/dedupe_set.h
index 8cdb180..2c4a689 100644
--- a/compiler/utils/dedupe_set.h
+++ b/compiler/utils/dedupe_set.h
@@ -99,7 +99,7 @@
     return hashed_key.store_ptr;
   }
 
-  explicit DedupeSet(const char* set_name, SwapAllocator<void>& alloc)
+  DedupeSet(const char* set_name, SwapAllocator<void>& alloc)
       : allocator_(alloc), hash_time_(0) {
     for (HashType i = 0; i < kShard; ++i) {
       std::ostringstream oss;
diff --git a/compiler/utils/dex_cache_arrays_layout.h b/compiler/utils/dex_cache_arrays_layout.h
index 8f98ea1..2a109bd 100644
--- a/compiler/utils/dex_cache_arrays_layout.h
+++ b/compiler/utils/dex_cache_arrays_layout.h
@@ -37,7 +37,7 @@
   }
 
   // Construct a layout for a particular dex file.
-  explicit DexCacheArraysLayout(size_t pointer_size, const DexFile* dex_file);
+  DexCacheArraysLayout(size_t pointer_size, const DexFile* dex_file);
 
   bool Valid() const {
     return Size() != 0u;
diff --git a/compiler/utils/managed_register.h b/compiler/utils/managed_register.h
index bb62bca..893daff 100644
--- a/compiler/utils/managed_register.h
+++ b/compiler/utils/managed_register.h
@@ -95,7 +95,7 @@
   explicit ManagedRegisterSpill(const ManagedRegister& other)
       : ManagedRegister(other), size_(-1), spill_offset_(-1) { }
 
-  explicit ManagedRegisterSpill(const ManagedRegister& other, int32_t size)
+  ManagedRegisterSpill(const ManagedRegister& other, int32_t size)
       : ManagedRegister(other), size_(size), spill_offset_(-1) { }
 
   int32_t getSpillOffset() {
diff --git a/compiler/utils/mips/assembler_mips.h b/compiler/utils/mips/assembler_mips.h
index 0d1b82c..df95dad 100644
--- a/compiler/utils/mips/assembler_mips.h
+++ b/compiler/utils/mips/assembler_mips.h
@@ -283,7 +283,7 @@
 // Slowpath entered when Thread::Current()->_exception is non-null
 class MipsExceptionSlowPath FINAL : public SlowPath {
  public:
-  explicit MipsExceptionSlowPath(MipsManagedRegister scratch, size_t stack_adjust)
+  MipsExceptionSlowPath(MipsManagedRegister scratch, size_t stack_adjust)
       : scratch_(scratch), stack_adjust_(stack_adjust) {}
   virtual void Emit(Assembler *sp_asm) OVERRIDE;
  private:
diff --git a/compiler/utils/mips64/assembler_mips64.h b/compiler/utils/mips64/assembler_mips64.h
index 47b146a..31130ea 100644
--- a/compiler/utils/mips64/assembler_mips64.h
+++ b/compiler/utils/mips64/assembler_mips64.h
@@ -354,7 +354,7 @@
 // Slowpath entered when Thread::Current()->_exception is non-null
 class Mips64ExceptionSlowPath FINAL : public SlowPath {
  public:
-  explicit Mips64ExceptionSlowPath(Mips64ManagedRegister scratch, size_t stack_adjust)
+  Mips64ExceptionSlowPath(Mips64ManagedRegister scratch, size_t stack_adjust)
       : scratch_(scratch), stack_adjust_(stack_adjust) {}
   virtual void Emit(Assembler *sp_asm) OVERRIDE;
  private:
diff --git a/compiler/utils/x86/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index d9c1b40..37c69fe 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -205,7 +205,7 @@
 
 class X86Assembler FINAL : public Assembler {
  public:
-  explicit X86Assembler() {}
+  X86Assembler() {}
   virtual ~X86Assembler() {}
 
   /*