Move large file source def to code

Makefile

@@ -10,7 +10,7 @@ INSTALL_PREFIX = dist
 RUNTIME_ASSERT = true
 
 # Internal variables
-override CFLAGS              = -Wall -Wextra -Werror -pedantic -Isrc -D_LARGEFILE64_SOURCE
+override CFLAGS              = -Wall -Wextra -Werror -pedantic -Isrc
 override LIBFLAGS            = -fPIC
 override CSTD               := -std=gnu11
 override CXXSTD             := -std=gnu++11