ELF: Updated comments for ET_EXEC and ET_DYN

include/elf/common.h has

 #define ET_EXEC         2       /* Executable file */
 #define ET_DYN          3       /* Shared object file */

These predate PIE:

https://groups.google.com/forum/#!topic/generic-abi/mBKlSNldFW4

Updated comments to

 #define ET_EXEC         2       /* Position-dependent executable file */
 #define ET_DYN          3       /* Position-independent executable or
                                    shared object file */

	* elf/common.h: Update comments for ET_EXEC and ET_DYN.

include/ChangeLog

@@ -1,3 +1,7 @@
+2020-05-25  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* elf/common.h: Update comments for ET_EXEC and ET_DYN.
+
 2020-05-20  Nelson Chu  <nelson.chu@sifive.com>
 
 	* opcode/riscv.h: Include "bfd.h" to support bfd_boolean.

include/elf/common.h

@@ -91,8 +91,9 @@
 
 #define ET_NONE		0	/* No file type */
 #define ET_REL		1	/* Relocatable file */
-#define ET_EXEC		2	/* Executable file */
-#define ET_DYN		3	/* Shared object file */
+#define ET_EXEC		2	/* Position-dependent executable file */
+#define ET_DYN		3	/* Position-independent executable or
+				   shared object file */
 #define ET_CORE		4	/* Core file */
 #define ET_LOOS		0xFE00	/* Operating system-specific */
 #define ET_HIOS		0xFEFF	/* Operating system-specific */