add POW, SQRT, PACKMAP, PACKSTRUCT; fix GAS price for PACK, UNPACK (#1350)

Author: Hecate2

docs/en-us/reference/neo_vm.md

@@ -777,6 +777,22 @@ Copy, remove and swap the elements of the stack.
 | Fee | 0.00000008 GAS                                          |
 | Function   | Returns the remainder after dividing a by b. |
 
+#### POW
+
+| Instruction | POW                                                |
+| ----------- | -------------------------------------------------- |
+| Bytecode    | 0xA3                                               |
+| Fee         | 0.00000064 GAS                                     |
+| Function    | The result of raising value to the exponent power. |
+
+#### SQRT
+
+| Instruction | SQRT                                           |
+| ----------- | ---------------------------------------------- |
+| Bytecode    | 0xA4                                           |
+| Fee         | 0.00000064 GAS                                 |
+| Function    | Returns the square root of a specified number. |
+
 #### SHL
 
 | Instruction   | SHL                              |
@@ -903,20 +919,36 @@ Copy, remove and swap the elements of the stack.
 
 It has implemented common operations for array, map, struct, etc.
 
+#### PACKMAP
+
+| Instruction | PACKMAP                                                      |
+| ----------- | ------------------------------------------------------------ |
+| Bytecode    | 0xBE                                                         |
+| Fee         | 0.00002048 GAS                                               |
+| Function    | A value n is taken from top of main stack. The next n*2 items on main stack are removed, put inside n-sized map and this map is put on top of the main stack. |
+
+#### PACKSTRUCT
+
+| Instruction | PACKSTRUCT                                                   |
+| ----------- | ------------------------------------------------------------ |
+| Bytecode    | 0xBF                                                         |
+| Fee         | 0.00002048 GAS                                               |
+| Function    | A value n is taken from top of main stack. The next n items on main stack are removed, put inside n-sized struct and this struct is put on top of the main stack. |
+
 #### PACK
 
 | Instruction   | PACK                              |
 |----------|-----------------------------------|
 | Bytecode | 0xC0                              |
-| Fee | 0.00000512 GAS                                          |
+| Fee | 0.00002048 GAS                                       |
 | Function   | A value n is taken from top of main stack. The next n items on main stack are removed, put inside n-sized array and this array is put on top of the main stack. |
 
 #### UNPACK
 
 | Instruction   | UNPACK                             |
 |----------|------------------------------------|
 | Bytecode | 0xC1                               |
-| Fee | 0.00000512 GAS                                          |
+| Fee | 0.00002048 GAS                                       |
 | Function   | An array is removed from top of the main stack. Its elements are put on top of the main stack (in reverse order) and the array size is also put on main stack. |
 
 #### NEWARRAY0

docs/zh-cn/reference/neo_vm.md

@@ -776,6 +776,22 @@ NeoVM虚拟机一共实现了189个指令，类别如下
 | 系统费 | 0.00000008 GAS                         |
 | 功能   | 用计算栈第二个BigInteger除以第一个BigInteger取余。 |
 
+#### POW
+
+| 指令   | POW                                                          |
+| ------ | ------------------------------------------------------------ |
+| 字节码 | 0xA3                                                         |
+| 系统费 | 0.00000064 GAS                                               |
+| 功能   | 用计算栈第二个BigInteger为底数，第一个integer为指数，求乘方。 |
+
+#### SQRT
+
+| 指令   | SQRT                                                         |
+| ------ | ------------------------------------------------------------ |
+| 字节码 | 0xA4                                                         |
+| 系统费 | 0.00000064 GAS                                               |
+| 功能   | 求计算栈第一个非负BigInteger的开方，并向下取整为BigInteger。 |
+
 #### SHL
 
 | 指令   | SHL                              |
@@ -899,20 +915,36 @@ NeoVM虚拟机一共实现了189个指令，类别如下
 ### 高级数据结构
 实现对Array、Map、Struct等的常用操作。
 
+#### PACKMAP
+
+| 指令   | PACKMAP                                                      |
+| ------ | ------------------------------------------------------------ |
+| 字节码 | 0xBE                                                         |
+| 系统费 | 0.00002048 GAS                                               |
+| 功能   | 将计算栈栈顶的2n个元素打包成Map。第1个为key，第2个为第1个的value。 |
+
+#### PACKSTRUCT
+
+| 指令   | PACKSTRUCT                          |
+| ------ | ----------------------------------- |
+| 字节码 | 0xBF                                |
+| 系统费 | 0.00002048 GAS                      |
+| 功能   | 将计算栈栈顶的n个元素打包成结构体。 |
+
 #### PACK
 
 | 指令   | PACK                              |
 | ------ | --------------------------------- |
 | 字节码 | 0xC0                              |
-| 系统费 | 0.00000512 GAS                    |
+| 系统费 | 0.00002048 GAS                    |
 | 功能   | 将计算栈栈顶的n个元素打包成数组。 |
 
 #### UNPACK
 
 | 指令   | UNPACK                             |
 | ------ | ---------------------------------- |
 | 字节码 | 0xC1                               |
-| 系统费 | 0.00000512 GAS                     |
+| 系统费 | 0.00002048 GAS                     |
 | 功能   | 将计算栈栈顶的数组拆包成元素序列。 |
 
 #### NEWARRAY0