elf: Add STT_GNU_IFUNC from glibc

perf in upstream Linux kernel 3.17 onwards expects STT_GNU_IFUNC
replicate it from glibc

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

include/elf.h

@@ -566,6 +566,7 @@ typedef struct
 #define STB_WEAK	2		/* Weak symbol */
 #define	STB_NUM		3		/* Number of defined types.  */
 #define STB_LOOS	10		/* Start of OS-specific */
+#define STB_GNU_UNIQUE	10		/* Unique symbol.  */
 #define STB_HIOS	12		/* End of OS-specific */
 #define STB_LOPROC	13		/* Start of processor-specific */
 #define STB_HIPROC	15		/* End of processor-specific */
@@ -581,6 +582,7 @@ typedef struct
 #define STT_TLS		6		/* Symbol is thread-local data object*/
 #define	STT_NUM		7		/* Number of defined types.  */
 #define STT_LOOS	10		/* Start of OS-specific */
+#define STT_GNU_IFUNC	10		/* Symbol is indirect code object */
 #define STT_HIOS	12		/* End of OS-specific */
 #define STT_LOPROC	13		/* Start of processor-specific */
 #define STT_HIPROC	15		/* End of processor-specific */