Add arch-x86_64/include/machine.

This is basically the other half of I5de76f6c46ac87779f207d568a86bb453e2414de
from Pavel Chupin <pavel.v.chupin@intel.com>, but taking the exact upstream
_types.h instead of the modified version. (I was confused when I suggested
otherwise.)

I've also cleaned up the internal_types.h situation; we weren't gaining
anything from these empty files, and there is no upstream internal_types.h
for x86_64.

Change-Id: I802a9a6a8df1c979e820659212c75a47c2ef392e
diff --git a/libc/arch-x86_64/include/machine/elf_machdep.h b/libc/arch-x86_64/include/machine/elf_machdep.h
new file mode 100644
index 0000000..20f8c6d
--- /dev/null
+++ b/libc/arch-x86_64/include/machine/elf_machdep.h
@@ -0,0 +1,55 @@
+/*	$NetBSD: elf_machdep.h,v 1.4 2010/03/18 08:28:33 cegger Exp $	*/
+
+#if !defined __i386__
+
+#define	ELF32_MACHDEP_ENDIANNESS	ELFDATA2LSB
+#define	ELF32_MACHDEP_ID_CASES						\
+		case EM_386:						\
+			break;
+
+#define	ELF64_MACHDEP_ENDIANNESS	ELFDATA2LSB
+#define	ELF64_MACHDEP_ID_CASES						\
+		case EM_X86_64:						\
+			break;
+
+#define	ELF32_MACHDEP_ID	EM_386
+#define	ELF64_MACHDEP_ID	EM_X86_64
+
+#define ARCH_ELFSIZE		64	/* MD native binary size */
+
+/* x86-64 relocations */
+
+#define R_X86_64_NONE		0
+#define R_X86_64_64		1
+#define R_X86_64_PC32		2
+#define R_X86_64_GOT32		3
+#define R_X86_64_PLT32		4
+#define R_X86_64_COPY		5
+#define R_X86_64_GLOB_DAT	6
+#define R_X86_64_JUMP_SLOT	7
+#define R_X86_64_RELATIVE	8
+#define R_X86_64_GOTPCREL	9
+#define R_X86_64_32		10
+#define R_X86_64_32S		11
+#define R_X86_64_16		12
+#define R_X86_64_PC16		13
+#define R_X86_64_8		14
+#define R_X86_64_PC8		15
+
+/* TLS relocations */
+#define R_X86_64_DTPMOD64	16
+#define R_X86_64_DTPOFF64	17
+#define R_X86_64_TPOFF64	18
+#define R_X86_64_TLSGD		19
+#define R_X86_64_TLSLD		20
+#define R_X86_64_DTPOFF32	21
+#define R_X86_64_GOTTPOFF	22
+#define R_X86_64_TPOFF32	23
+
+#define	R_TYPE(name)	__CONCAT(R_X86_64_,name)
+
+#else	/*	!__i386__	*/
+
+#include <i386/elf_machdep.h>
+
+#endif	/*	!__i386__	*/