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-arm/arm.mk b/libc/arch-arm/arm.mk
index dea303a..0717306 100644
--- a/libc/arch-arm/arm.mk
+++ b/libc/arch-arm/arm.mk
@@ -1,7 +1,7 @@
 _LIBC_ARCH_COMMON_SRC_FILES := \
     arch-arm/bionic/abort_arm.S \
     arch-arm/bionic/atomics_arm.c \
-    arch-arm/bionic/clone.S \
+    arch-arm/bionic/__bionic_clone.S \
     arch-arm/bionic/eabi.c \
     arch-arm/bionic/_exit_with_stack_teardown.S \
     arch-arm/bionic/futex_arm.S \
diff --git a/libc/arch-arm/bionic/clone.S b/libc/arch-arm/bionic/__bionic_clone.S
similarity index 100%
rename from libc/arch-arm/bionic/clone.S
rename to libc/arch-arm/bionic/__bionic_clone.S
diff --git a/libc/arch-arm/syscalls.mk b/libc/arch-arm/syscalls.mk
index f8bb15a..c0438b4 100644
--- a/libc/arch-arm/syscalls.mk
+++ b/libc/arch-arm/syscalls.mk
@@ -1,7 +1,6 @@
 # Generated by gensyscalls.py. Do not edit.
 syscall_src :=
 syscall_src += arch-arm/syscalls/__brk.S
-syscall_src += arch-arm/syscalls/__clone.S
 syscall_src += arch-arm/syscalls/__epoll_pwait.S
 syscall_src += arch-arm/syscalls/__exit.S
 syscall_src += arch-arm/syscalls/__fcntl64.S
diff --git a/libc/arch-arm/syscalls/__clone.S b/libc/arch-arm/syscalls/__clone.S
deleted file mode 100644
index fb074bc..0000000
--- a/libc/arch-arm/syscalls/__clone.S
+++ /dev/null
@@ -1,17 +0,0 @@
-/* Generated by gensyscalls.py. Do not edit. */
-
-#include <private/bionic_asm.h>
-
-ENTRY(__clone)
-    mov     ip, sp
-    .save   {r4, r5, r6, r7}
-    stmfd   sp!, {r4, r5, r6, r7}
-    ldmfd   ip, {r4, r5, r6}
-    ldr     r7, =__NR_clone
-    swi     #0
-    ldmfd   sp!, {r4, r5, r6, r7}
-    cmn     r0, #(MAX_ERRNO + 1)
-    bxls    lr
-    neg     r0, r0
-    b       __set_errno
-END(__clone)