enums from extensions shold be in a const section. (Nim)
This is my generated var section. 

```Nim
# Extensions
var
  GLAD_GL_ARB_debug_output*: bool
  GL_DEBUG_OUTPUT_SYNCHRONOUS_ARB*: GLenum = GLenum(0x8242)
  GL_DEBUG_NEXT_LOGGED_MESSAGE_LENGTH_ARB*: GLenum = GLenum(0x8243)
  GL_DEBUG_CALLBACK_FUNCTION_ARB*: GLenum = GLenum(0x8244)
  GL_DEBUG_CALLBACK_USER_PARAM_ARB*: GLenum = GLenum(0x8245)
  GL_DEBUG_SOURCE_API_ARB*: GLenum = GLenum(0x8246)
  GL_DEBUG_SOURCE_WINDOW_SYSTEM_ARB*: GLenum = GLenum(0x8247)
  GL_DEBUG_SOURCE_SHADER_COMPILER_ARB*: GLenum = GLenum(0x8248)
  GL_DEBUG_SOURCE_THIRD_PARTY_ARB*: GLenum = GLenum(0x8249)
  GL_DEBUG_SOURCE_APPLICATION_ARB*: GLenum = GLenum(0x824A)
  GL_DEBUG_SOURCE_OTHER_ARB*: GLenum = GLenum(0x824B)
  GL_DEBUG_TYPE_ERROR_ARB*: GLenum = GLenum(0x824C)
  GL_DEBUG_TYPE_DEPRECATED_BEHAVIOR_ARB*: GLenum = GLenum(0x824D)
  GL_DEBUG_TYPE_UNDEFINED_BEHAVIOR_ARB*: GLenum = GLenum(0x824E)
  GL_DEBUG_TYPE_PORTABILITY_ARB*: GLenum = GLenum(0x824F)
  GL_DEBUG_TYPE_PERFORMANCE_ARB*: GLenum = GLenum(0x8250)
  GL_DEBUG_TYPE_OTHER_ARB*: GLenum = GLenum(0x8251)
  GL_MAX_DEBUG_MESSAGE_LENGTH_ARB*: GLenum = GLenum(0x9143)
  GL_MAX_DEBUG_LOGGED_MESSAGES_ARB*: GLenum = GLenum(0x9144)
  GL_DEBUG_LOGGED_MESSAGES_ARB*: GLenum = GLenum(0x9145)
  GL_DEBUG_SEVERITY_HIGH_ARB*: GLenum = GLenum(0x9146)
  GL_DEBUG_SEVERITY_MEDIUM_ARB*: GLenum = GLenum(0x9147)
  GL_DEBUG_SEVERITY_LOW_ARB*: GLenum = GLenum(0x9148)

  GLAD_GL_ARB_direct_state_access*: bool
  GL_TEXTURE_TARGET*: GLenum = GLenum(0x1006)
  GL_QUERY_TARGET*: GLenum = GLenum(0x82EA)
  GL_TEXTURE_BINDING_CUBE_MAP_ARRAY*: GLenum = GLenum(0x900A)

```

But for example when I want to use `GL_DEBUG_TYPE_ERROR_ARB` is a switch case, that value needs to be const. Therefore the generated source should look like this:


```Nim
# Extensions
const
  # GL_ARB_debug_output
  GL_DEBUG_OUTPUT_SYNCHRONOUS_ARB*: GLenum = GLenum(0x8242)
  GL_DEBUG_NEXT_LOGGED_MESSAGE_LENGTH_ARB*: GLenum = GLenum(0x8243)
  GL_DEBUG_CALLBACK_FUNCTION_ARB*: GLenum = GLenum(0x8244)
  GL_DEBUG_CALLBACK_USER_PARAM_ARB*: GLenum = GLenum(0x8245)
  GL_DEBUG_SOURCE_API_ARB*: GLenum = GLenum(0x8246)
  GL_DEBUG_SOURCE_WINDOW_SYSTEM_ARB*: GLenum = GLenum(0x8247)
  GL_DEBUG_SOURCE_SHADER_COMPILER_ARB*: GLenum = GLenum(0x8248)
  GL_DEBUG_SOURCE_THIRD_PARTY_ARB*: GLenum = GLenum(0x8249)
  GL_DEBUG_SOURCE_APPLICATION_ARB*: GLenum = GLenum(0x824A)
  GL_DEBUG_SOURCE_OTHER_ARB*: GLenum = GLenum(0x824B)
  GL_DEBUG_TYPE_ERROR_ARB*: GLenum = GLenum(0x824C)
  GL_DEBUG_TYPE_DEPRECATED_BEHAVIOR_ARB*: GLenum = GLenum(0x824D)
  GL_DEBUG_TYPE_UNDEFINED_BEHAVIOR_ARB*: GLenum = GLenum(0x824E)
  GL_DEBUG_TYPE_PORTABILITY_ARB*: GLenum = GLenum(0x824F)
  GL_DEBUG_TYPE_PERFORMANCE_ARB*: GLenum = GLenum(0x8250)
  GL_DEBUG_TYPE_OTHER_ARB*: GLenum = GLenum(0x8251)
  GL_MAX_DEBUG_MESSAGE_LENGTH_ARB*: GLenum = GLenum(0x9143)
  GL_MAX_DEBUG_LOGGED_MESSAGES_ARB*: GLenum = GLenum(0x9144)
  GL_DEBUG_LOGGED_MESSAGES_ARB*: GLenum = GLenum(0x9145)
  GL_DEBUG_SEVERITY_HIGH_ARB*: GLenum = GLenum(0x9146)
  GL_DEBUG_SEVERITY_MEDIUM_ARB*: GLenum = GLenum(0x9147)
  GL_DEBUG_SEVERITY_LOW_ARB*: GLenum = GLenum(0x9148)
  # GL_ARB_direct_state_access
  GL_TEXTURE_TARGET*: GLenum = GLenum(0x1006)
  GL_QUERY_TARGET*: GLenum = GLenum(0x82EA)
  GL_TEXTURE_BINDING_CUBE_MAP_ARRAY*: GLenum = GLenum(0x900A)

var
  GLAD_GL_ARB_debug_output*: bool
  GLAD_GL_ARB_direct_state_access*: bool
  glDebugMessageControlARB*: proc (source: GLenum, `type`: GLenum, severity: GLenum, count: GLsizei, ids: ptr GLuint, enabled: GLboolean) {.cdecl.}
  glDebugMessageInsertARB*: proc (source: GLenum, `type`: GLenum, id: GLuint, severity: GLenum, length: GLsizei, buf: cstring) {.cdecl.}
  glDebugMessageCallbackARB*: proc (callback: GLDEBUGPROCARB, userParam: pointer) {.cdecl.}
  glGetDebugMessageLogARB*: proc (count: GLuint, bufSize: GLsizei, sources: ptr GLenum, types: ptr GLenum, ids: ptr GLuint, severities: ptr GLenum, lengths: ptr
```
