Add support for PaX ELF markings

Patch by Kevin F. Quinn <kevquinn@gentoo.org>

http://bugs.gentoo.org/115100

--- a/libelf/elf.h
+++ b/libelf/elf.h
@@ -568,6 +568,7 @@
 #define PT_GNU_EH_FRAME	0x6474e550	/* GCC .eh_frame_hdr segment */
 #define PT_GNU_STACK	0x6474e551	/* Indicates stack executability */
 #define PT_GNU_RELRO	0x6474e552	/* Read-only after relocation */
+#define PT_PAX_FLAGS    0x65041580  /* Indicates PaX flag markings */
 #define PT_LOSUNW	0x6ffffffa
 #define PT_SUNWBSS	0x6ffffffa	/* Sun Specific segment */
 #define PT_SUNWSTACK	0x6ffffffb	/* Stack segment */
--- a/src/elflint.c
+++ b/src/elflint.c
@@ -3187,6 +3187,7 @@
 
       if (phdr->p_type >= PT_NUM && phdr->p_type != PT_GNU_EH_FRAME
 	  && phdr->p_type != PT_GNU_STACK && phdr->p_type != PT_GNU_RELRO
+	  && phdr->p_type != PT_PAX_FLAGS
 	  /* Check for a known machine-specific type.  */
 	  && ebl_segment_type_name (ebl, phdr->p_type, NULL, 0) == NULL)
 	ERROR (gettext ("\