No-op DT_AARCH64_MEMTAG_* entries

As of https://reviews.llvm.org/D143769, binaries (with -fsanitize=memtag-*)
have DT_AARCH64_MEMTAG_* dynamic entries, as per the AArch64 MemtagABI.
Android uses an OS-specific ELF note for MTE config, but we should
migrate to the new thing (while preserving backwards compatibility).

Without actually doing the migration right now, just handle these new
entries. Otherwise, you get a whole bunch of logspam about the
unrecognised dynamic entries.

Bug: 274032544
Test: Build android, don't get logspam.
Change-Id: I5c8b59f77a0058e5b93335e269d558a5014f2260
diff --git a/libc/include/bits/elf_common.h b/libc/include/bits/elf_common.h
index ea833f4..b3c57a2 100644
--- a/libc/include/bits/elf_common.h
+++ b/libc/include/bits/elf_common.h
@@ -418,12 +418,12 @@
 #define	SHT_HIOS		0x6fffffff	/* Last of OS specific semantics */
 #define	SHT_LOPROC		0x70000000	/* reserved range for processor */
 #define	SHT_X86_64_UNWIND	0x70000001	/* unwind information */
-#define	SHT_AMD64_UNWIND	SHT_X86_64_UNWIND 
+#define	SHT_AMD64_UNWIND	SHT_X86_64_UNWIND
 
 #define	SHT_ARM_EXIDX		0x70000001	/* Exception index table. */
-#define	SHT_ARM_PREEMPTMAP	0x70000002	/* BPABI DLL dynamic linking 
+#define	SHT_ARM_PREEMPTMAP	0x70000002	/* BPABI DLL dynamic linking
 						   pre-emption map. */
-#define	SHT_ARM_ATTRIBUTES	0x70000003	/* Object file compatibility 
+#define	SHT_ARM_ATTRIBUTES	0x70000003	/* Object file compatibility
 						   attributes. */
 #define	SHT_ARM_DEBUGOVERLAY	0x70000004	/* See DBGOVL for details. */
 #define	SHT_ARM_OVERLAYSECTION	0x70000005	/* See DBGOVL for details. */
@@ -648,6 +648,11 @@
 #define	DT_AARCH64_BTI_PLT		0x70000001
 #define	DT_AARCH64_PAC_PLT		0x70000003
 #define	DT_AARCH64_VARIANT_PCS		0x70000005
+#define DT_AARCH64_MEMTAG_MODE		0x70000009
+#define DT_AARCH64_MEMTAG_HEAP		0x7000000b
+#define DT_AARCH64_MEMTAG_STACK		0x7000000c
+#define DT_AARCH64_MEMTAG_GLOBALS	0x7000000d
+#define DT_AARCH64_MEMTAG_GLOBALSSZ	0x7000000f
 
 #define	DT_ARM_SYMTABSZ			0x70000001
 #define	DT_ARM_PREEMPTMAP		0x70000002