Initial support for GNU/Hurd.

Identify the platform as "hurd", and make use of stuff already used for Linux or *BSD when possible.
The location of the premake binary (premake_locate) is not implemented, since there is currently no way to do that on GNU/Hurd.

premake4.lua

@@ -54,7 +54,7 @@
 		configuration "windows"
 			links { "ole32" }
 
-		configuration "linux or bsd"
+		configuration "linux or bsd or hurd"
 			defines     { "LUA_USE_POSIX", "LUA_USE_DLOPEN" }
 			links       { "m" }
 			linkoptions { "-rdynamic" }
@@ -62,6 +62,9 @@
 		configuration "linux"
 			links       { "dl" }
 
+		configuration "hurd"
+			links       { "dl" }
+
 		configuration "macosx"
 			defines     { "LUA_USE_MACOSX" }
 			links       { "CoreServices.framework" }

src/base/cmdline.lua

@@ -54,6 +54,7 @@
 			{ "aix",      "IBM AIX" },
 			{ "bsd",      "OpenBSD, NetBSD, or FreeBSD" },
 			{ "haiku",    "Haiku" },
+			{ "hurd",     "GNU/Hurd" },
 			{ "linux",    "Linux" },
 			{ "macosx",   "Apple Mac OS X" },
 			{ "solaris",  "Solaris" },

src/host/os_getversion.c

@@ -218,7 +218,7 @@ void getversion(struct OsVersionInfo* info)
 
 /*************************************************************/
 
-#elif defined(PLATFORM_BSD) || defined(PLATFORM_LINUX) || defined(PLATFORM_SOLARIS)
+#elif defined(PLATFORM_BSD) || defined(PLATFORM_LINUX) || defined(PLATFORM_SOLARIS) || defined(PLATFORM_HURD)
 
 #include <string.h>
 #include <sys/utsname.h>

src/host/premake.h

@@ -30,6 +30,9 @@
 #elif defined (_AIX)
 #define PLATFORM_AIX  (1)
 #define PLATFORM_STRING  "aix"
+#elif defined (__GNU__)
+#define PLATFORM_HURD  (1)
+#define PLATFORM_STRING  "hurd"
 #else
 #define PLATFORM_WINDOWS  (1)
 #define PLATFORM_STRING   "windows"