Separate mmap area from program loading (relocation) area

We need to separate the two because the heap of a PIE is created in
the area to which it is mapped.

Related commits:

b1309a5d: PIE is mapped at map_end instead of at
          user_start
c4219655: Interpreter is mapped to map_start to make a
          system call that dereferences a NULL pointer fail

[dominique.martinet@cea.fr: Also add ULONG_MAX and friend macroes,
 used for data_min]
[ken.sato.ty@hitachi-solutions.com: fix execve]
Change-Id: I8ecaf22b7965090ab67bebece57c68283ba23664

lib/include/limits.h

@@ -15,6 +15,10 @@
 
 #define INT_MAX 0x7fffffff
 #define INT_MIN -0x80000000
+#define UINT_MAX 0xffffffff
+#define LONG_MAX 0x7fffffffffffffffL
+#define LONG_MIN -0x8000000000000000L
+#define ULONG_MAX 0xffffffffffffffffL
 #define IOV_MAX 1024
 
 #ifndef PATH_MAX