Clean up forking and cloning.

The kernel now maintains the pthread_internal_t::tid field for us,
and __clone was only used in one place so let's inline it so we don't
have to leave such a dangerous function lying around. Also rename
files to match their content and remove some useless #includes.

Change-Id: I24299fb4a940e394de75f864ee36fdabbd9438f9
diff --git a/libc/arch-x86/bionic/clone.S b/libc/arch-x86/bionic/__bionic_clone.S
similarity index 100%
rename from libc/arch-x86/bionic/clone.S
rename to libc/arch-x86/bionic/__bionic_clone.S
diff --git a/libc/arch-x86/syscalls.mk b/libc/arch-x86/syscalls.mk
index b6a1e38..780972f 100644
--- a/libc/arch-x86/syscalls.mk
+++ b/libc/arch-x86/syscalls.mk
@@ -1,7 +1,6 @@
 # Generated by gensyscalls.py. Do not edit.
 syscall_src :=
 syscall_src += arch-x86/syscalls/__brk.S
-syscall_src += arch-x86/syscalls/__clone.S
 syscall_src += arch-x86/syscalls/__epoll_pwait.S
 syscall_src += arch-x86/syscalls/__exit.S
 syscall_src += arch-x86/syscalls/__fcntl64.S
diff --git a/libc/arch-x86/syscalls/__clone.S b/libc/arch-x86/syscalls/__clone.S
deleted file mode 100644
index 2ff8fcd..0000000
--- a/libc/arch-x86/syscalls/__clone.S
+++ /dev/null
@@ -1,32 +0,0 @@
-/* Generated by gensyscalls.py. Do not edit. */
-
-#include <private/bionic_asm.h>
-
-ENTRY(__clone)
-    pushl   %ebx
-    pushl   %ecx
-    pushl   %edx
-    pushl   %esi
-    pushl   %edi
-    mov     24(%esp), %ebx
-    mov     28(%esp), %ecx
-    mov     32(%esp), %edx
-    mov     36(%esp), %esi
-    mov     40(%esp), %edi
-    movl    $__NR_clone, %eax
-    int     $0x80
-    cmpl    $-MAX_ERRNO, %eax
-    jb      1f
-    negl    %eax
-    pushl   %eax
-    call    __set_errno
-    addl    $4, %esp
-    orl     $-1, %eax
-1:
-    popl    %edi
-    popl    %esi
-    popl    %edx
-    popl    %ecx
-    popl    %ebx
-    ret
-END(__clone)
diff --git a/libc/arch-x86/x86.mk b/libc/arch-x86/x86.mk
index 5911ad9..9c74084 100644
--- a/libc/arch-x86/x86.mk
+++ b/libc/arch-x86/x86.mk
@@ -1,5 +1,5 @@
 _LIBC_ARCH_COMMON_SRC_FILES := \
-    arch-x86/bionic/clone.S \
+    arch-x86/bionic/__bionic_clone.S \
     arch-x86/bionic/_exit_with_stack_teardown.S \
     arch-x86/bionic/futex_x86.S \
     arch-x86/bionic/__get_sp.S \