Minimize uses of lazy initialization by adding explicit initialization functions.

src/x64/disasm-x64.cc

Index: src/x64/disasm-x64.cc
diff --git a/src/x64/disasm-x64.cc b/src/x64/disasm-x64.cc
index adeda0bb08b293378791710509874694bdf3633f..7ed81b47e147ac41262deea98f62646ffb0b218b 100644
--- a/src/x64/disasm-x64.cc
+++ b/src/x64/disasm-x64.cc
@@ -315,7 +315,8 @@ class DisassemblerX64 {
         rex_(0),
         operand_size_(0),
         group_1_prefix_(0),
-        byte_size_operand_(false) {
+        byte_size_operand_(false),
+        instruction_table_(instruction_table.Pointer()) {
     tmp_buffer_[0] = '\0';
   }
 
@@ -344,6 +345,7 @@ class DisassemblerX64 {
   byte group_1_prefix_;  // 0xF2, 0xF3, or (if no group 1 prefix is present) 0.
   // Byte size operand override.
   bool byte_size_operand_;
+  const InstructionTable* const instruction_table_;
 
   void setRex(byte rex) {
     ASSERT_EQ(0x40, rex & 0xF0);
@@ -1340,7 +1342,7 @@ int DisassemblerX64::InstructionDecode(v8::internal::Vector<char> out_buffer,
     data++;
   }
 
-  const InstructionDesc& idesc = instruction_table.Get().Get(current);
+  const InstructionDesc& idesc = instruction_table_->Get(current);
   byte_size_operand_ = idesc.byte_size_operation;
   switch (idesc.type) {
     case ZERO_OPERANDS_INSTR: