need to remove vm2_defined sentinel

why:
  subsequent development will compile sources as main without setting
  the vm2_enabled flag. also, the doc generator would fail an vm2 without
  setting the flag for the vm2 files.

nimbus/vm2/interpreter/utils/v2utils_numeric.nim

@@ -5,8 +5,6 @@
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}
 

nimbus/vm2/interpreter/v2forks.nim

@@ -5,8 +5,6 @@
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}
 

nimbus/vm2/interpreter/v2gas_costs.nim

@@ -5,8 +5,6 @@
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}
 

nimbus/vm2/v2computation.nim

@@ -5,8 +5,6 @@
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}
 

nimbus/vm2/v2interpreter.nim

@@ -8,8 +8,6 @@
 # at your option. This file may not be copied, modified, or distributed except
 # according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}
 

nimbus/vm2/v2memory.nim

@@ -5,8 +5,6 @@
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}
 

nimbus/vm2/v2message.nim

@@ -5,8 +5,6 @@
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}
 

nimbus/vm2/v2precompiles.nim

@@ -8,8 +8,6 @@
 # at your option. This file may not be copied, modified, or distributed except
 # according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}
 

nimbus/vm2/v2state.nim

@@ -8,8 +8,6 @@
 # at your option. This file may not be copied, modified, or distributed except
 # according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}
 

nimbus/vm2/v2state_transactions.nim

@@ -5,8 +5,6 @@
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}
 

nimbus/vm2/v2types.nim

@@ -8,8 +8,6 @@
 # at your option. This file may not be copied, modified, or distributed except
 # according to those terms.
 
-when not defined(vm2_enabled):
-  {.fatal: "Flags \"vm2_enabled\" must be defined"}
 when defined(evmc_enabled):
   {.fatal: "Flags \"evmc_enabled\" and \"vm2_enabled\" are mutually exclusive"}