[EraVM] Remove Value field from OpcodeEncoding

This field's value has no particular meaning neither in TableGen
nor in C++ and can be autogenerated if GenericEnum is ever desired.

Author: atrosinenko

llvm/lib/Target/EraVM/EraVMOpcodes.td

@@ -55,9 +55,7 @@ class isStackOut<DstMode dst> {
     !eq(dst, DstStackAbsolute));
 }
 
-class OpcodeEncoding<bits<4> val> {
-  bits<4> Value = val;
-
+class OpcodeEncoding {
   bits<11> SrcMultiplier = 0; // No in_any operand by default.
   bits<11> DstMultiplier = 0; // No out_any operand by default.
 
@@ -67,23 +65,23 @@ class OpcodeEncoding<bits<4> val> {
   // the beginning of InOperandList.
 }
 
-def DirectEncoding     : OpcodeEncoding<0>; // opcode ⇒ opcode
+def DirectEncoding     : OpcodeEncoding; // opcode ⇒ opcode
 let SrcMultiplier = 4, DstMultiplier = 1, IndexOfStackDstUse = 2 in
-def NopEncoding        : OpcodeEncoding<1>; // opcode src dst ⇒ opcode + 4 × src + 1 × dst
+def NopEncoding        : OpcodeEncoding; // opcode src dst ⇒ opcode + 4 × src + 1 × dst
 let SrcMultiplier = 8, DstMultiplier = 2, IndexOfStackDstUse = 2 in
-def ArithCommEncoding  : OpcodeEncoding<2>; // opcode src dst set_flags ⇒ opcode + 8 × src + 2 × dst + set_flags
+def ArithCommEncoding  : OpcodeEncoding; // opcode src dst set_flags ⇒ opcode + 8 × src + 2 × dst + set_flags
 let SrcMultiplier = 16, DstMultiplier = 4, IndexOfStackDstUse = 2 in
-def ArithNCommEncoding : OpcodeEncoding<3>; // opcode src dst swap set_flags ⇒ opcode + 16 × src + 4 × dst + 2 × set_flags + swap
+def ArithNCommEncoding : OpcodeEncoding; // opcode src dst swap set_flags ⇒ opcode + 16 × src + 4 × dst + 2 × set_flags + swap
 let SrcMultiplier = 8, DstMultiplier = 2, IndexOfStackDstUse = 2 in
-def ArithPtrEncoding   : OpcodeEncoding<4>; // opcode src dst swap ⇒ opcode + 8 × src + 2 × dst + swap
-def FarCallEncoding    : OpcodeEncoding<5>; // opcode is_shard is_static ⇒ opcode + 2 × is_static + is_shard
-def RetEncoding        : OpcodeEncoding<6>; // opcode to_label ⇒ opcode + to_label
+def ArithPtrEncoding   : OpcodeEncoding; // opcode src dst swap ⇒ opcode + 8 × src + 2 × dst + swap
+def FarCallEncoding    : OpcodeEncoding; // opcode is_shard is_static ⇒ opcode + 2 × is_static + is_shard
+def RetEncoding        : OpcodeEncoding; // opcode to_label ⇒ opcode + to_label
 let SrcMultiplier = 1 in
-def JumpEncoding       : OpcodeEncoding<7>; // opcode src ⇒ opcode + 1 × src
-def LoadPtrEncoding    : OpcodeEncoding<8>; // opcode inc ⇒ opcode + inc
-def HeapOpEncoding     : OpcodeEncoding<9>; // opcode src_special inc ⇒ opcode + 10 × src_special + inc
-def LogEncoding        : OpcodeEncoding<10>;// opcode is_first ⇒ opcode + is_first
-def StaticOpEncoding   : OpcodeEncoding<11>;// opcode src_special inc ⇒ opcode + 2 × src_special + inc
+def JumpEncoding       : OpcodeEncoding; // opcode src ⇒ opcode + 1 × src
+def LoadPtrEncoding    : OpcodeEncoding; // opcode inc ⇒ opcode + inc
+def HeapOpEncoding     : OpcodeEncoding; // opcode src_special inc ⇒ opcode + 10 × src_special + inc
+def LogEncoding        : OpcodeEncoding; // opcode is_first ⇒ opcode + is_first
+def StaticOpEncoding   : OpcodeEncoding; // opcode src_special inc ⇒ opcode + 2 × src_special + inc
 
 class ArithOpcEncoder<OpcodeEncoding encoding, bits<11> BaseOpcode,
                       SrcMode src, DstMode dst,