refactor: replace manual header guards with #pragma once

It is less error-prone than manually defining header guards. Pretty much
all compilers support it even if it's not part of the C standard.

src/nvim/lua/base64.h

@@ -1,5 +1,4 @@
-#ifndef NVIM_LUA_BASE64_H
-#define NVIM_LUA_BASE64_H
+#pragma once
 
 #include <lauxlib.h>
 #include <lua.h>
@@ -8,5 +7,3 @@
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "lua/base64.h.generated.h"
 #endif
-
-#endif  // NVIM_LUA_BASE64_H

src/nvim/lua/converter.h

@@ -1,5 +1,4 @@
-#ifndef NVIM_LUA_CONVERTER_H
-#define NVIM_LUA_CONVERTER_H
+#pragma once
 
 #include <lua.h>
 #include <stdbool.h>
@@ -16,4 +15,3 @@
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "lua/converter.h.generated.h"
 #endif
-#endif  // NVIM_LUA_CONVERTER_H

src/nvim/lua/executor.h

@@ -1,5 +1,4 @@
-#ifndef NVIM_LUA_EXECUTOR_H
-#define NVIM_LUA_EXECUTOR_H
+#pragma once
 
 #include <lauxlib.h>
 #include <lua.h>
@@ -47,5 +46,3 @@ typedef struct {
 
 EXTERN nlua_ref_state_t *nlua_global_refs INIT( = NULL);
 EXTERN bool nlua_disable_preload INIT( = false);
-
-#endif  // NVIM_LUA_EXECUTOR_H

src/nvim/lua/secure.h

@@ -1,5 +1,4 @@
-#ifndef NVIM_LUA_SECURE_H
-#define NVIM_LUA_SECURE_H
+#pragma once
 
 #include <lua.h>
 
@@ -8,5 +7,3 @@
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "lua/secure.h.generated.h"
 #endif
-
-#endif  // NVIM_LUA_SECURE_H

src/nvim/lua/spell.h

@@ -1,5 +1,4 @@
-#ifndef NVIM_LUA_SPELL_H
-#define NVIM_LUA_SPELL_H
+#pragma once
 
 #include <lauxlib.h>
 #include <lua.h>
@@ -8,5 +7,3 @@
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "lua/spell.h.generated.h"
 #endif
-
-#endif  // NVIM_LUA_SPELL_H

src/nvim/lua/stdlib.h

@@ -1,10 +1,7 @@
-#ifndef NVIM_LUA_STDLIB_H
-#define NVIM_LUA_STDLIB_H
+#pragma once
 
 #include <lua.h>
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "lua/stdlib.h.generated.h"
 #endif
-
-#endif  // NVIM_LUA_STDLIB_H

src/nvim/lua/treesitter.h

@@ -1,5 +1,4 @@
-#ifndef NVIM_LUA_TREESITTER_H
-#define NVIM_LUA_TREESITTER_H
+#pragma once
 
 #include <lauxlib.h>
 #include <lua.h>
@@ -10,5 +9,3 @@
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "lua/treesitter.h.generated.h"
 #endif
-
-#endif  // NVIM_LUA_TREESITTER_H

src/nvim/lua/xdiff.h

@@ -1,5 +1,4 @@
-#ifndef NVIM_LUA_XDIFF_H
-#define NVIM_LUA_XDIFF_H
+#pragma once
 
 #include <lauxlib.h>
 #include <lua.h>
@@ -8,5 +7,3 @@
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "lua/xdiff.h.generated.h"
 #endif
-
-#endif  // NVIM_LUA_XDIFF_H