style: fix cpp indentation

[Akim Demaille]

commit c53b37978414865082e3e3e23fec62d564f4b18c
Author: Akim Demaille <address@hidden>
Date:   Tue Oct 29 09:00:46 2019 +0100

    style: fix cpp indentation
    
    Reported by syntax-check.
    
    * src/system.h: here.

diff --git a/src/system.h b/src/system.h
index 17301491..35d39f40 100644
--- a/src/system.h
+++ b/src/system.h
@@ -75,16 +75,16 @@ typedef size_t uintptr_t;
 
 
 /* See https://lists.gnu.org/archive/html/bug-bison/2019-10/msg00061.html. */
-#if defined __GNUC__ && ! defined __clang__ && ! defined __ICC && __GNUC__ < 5
-# define IGNORE_TYPE_LIMITS_BEGIN \
-    _Pragma ("GCC diagnostic push") \
-    _Pragma ("GCC diagnostic ignored \"-Wtype-limits\"")
-# define IGNORE_TYPE_LIMITS_END \
-    _Pragma ("GCC diagnostic pop")
-#else
-# define IGNORE_TYPE_LIMITS_BEGIN
-# define IGNORE_TYPE_LIMITS_END
-#endif
+# if defined __GNUC__ && ! defined __clang__ && ! defined __ICC && __GNUC__ < 5
+#  define IGNORE_TYPE_LIMITS_BEGIN \
+     _Pragma ("GCC diagnostic push") \
+     _Pragma ("GCC diagnostic ignored \"-Wtype-limits\"")
+#  define IGNORE_TYPE_LIMITS_END \
+     _Pragma ("GCC diagnostic pop")
+# else
+#  define IGNORE_TYPE_LIMITS_BEGIN
+#  define IGNORE_TYPE_LIMITS_END
+# endif
 
 
 /*-----------------.