Update for PUSH ZERO

Instruction.cpp

@@ -74,6 +74,7 @@ static const std::map<Instruction,  InstructionInfo> c_instructionInfo =
     { Instruction::MSIZE,        { "MSIZE",               0,    1,  Tier::Base } },
     { Instruction::GAS,          { "GAS",                 0,    1,  Tier::Base } },
     { Instruction::JUMPDEST,     { "JUMPDEST",            0,    0,  Tier::Special } },
+    { Instruction::PUSH0,        { "PUSH0",               0,    1,  Tier::Base } },
     { Instruction::PUSH1,        { "PUSH1",               0,    1,  Tier::VeryLow } },
     { Instruction::PUSH2,        { "PUSH2",               0,    1,  Tier::VeryLow } },
     { Instruction::PUSH3,        { "PUSH3",               0,    1,  Tier::VeryLow } },

Instruction.h

@@ -83,6 +83,7 @@ enum class Instruction : uint8_t
     GAS,         ///< get the amount of available gas
     JUMPDEST,    ///< set a potential jump destination
 
+    PUSH0 = 0x5f,  ///< place the value 0 on stack
     PUSH1 = 0x60,  ///< place 1 byte item on stack
     PUSH2,         ///< place 2 byte item on stack
     PUSH3,         ///< place 3 byte item on stack

LegacyVM.cpp

@@ -1492,6 +1492,17 @@ void LegacyVM::interpretCases()
 #endif
         }
         CONTINUE
+        // EIP-3855. Code PUSH0 is similar to PUSH1 but pushes 0
+        // we need to increment program counter only by one since
+        // the value is not read from program code as in PUSH1
+        CASE( PUSH0 ) {
+            if (!m_schedule->havePush0)
+                throwBadInstruction();
+            ON_OP();
+            updateIOGas();
+            m_SPP[0] = 0;
+            ++m_PC;
+        };
 
         CASE(PUSH1)
         {

LegacyVMConfig.h

@@ -245,7 +245,7 @@ namespace dev
         &&BEGINDATA,                            \
         &&BEGINSUB,                             \
         &&INVALID,                              \
-        &&INVALID,                              \
+        &&PUSH0,                              \
         &&PUSH1, /* 60, */                      \
         &&PUSH2,                                \
         &&PUSH3,                                \