Remove C++ pseudo support

tests/arena/test_arena.h

@@ -3,10 +3,6 @@
 
 #include "wapp.h"
 
-#ifdef WAPP_PLATFORM_CPP
-BEGIN_C_LINKAGE
-#endif // WAPP_PLATFORM_CPP
-
 TestFuncResult test_arena_init(void);
 TestFuncResult test_arena_init_succeeds_when_reserving_very_large_size(void);
 TestFuncResult test_arena_alloc_succeeds_when_within_capacity(void);
@@ -16,8 +12,4 @@ TestFuncResult test_arena_realloc_smaller_size(void);
 TestFuncResult test_arena_clear(void);
 TestFuncResult test_arena_destroy(void);
 
-#ifdef WAPP_PLATFORM_CPP
-END_C_LINKAGE
-#endif // WAPP_PLATFORM_CPP
-
 #endif // !TEST_ARENA_H