Replace TLS_SLOT_BIONIC_PREINIT w/ shared globals

Instead of passing the address of a KernelArgumentBlock to libc.so for
initialization, use __loader_shared_globals() to initialize globals.

Most of the work happened in the previous CLs. This CL switches a few
KernelArgumentBlock::getauxval calls to [__bionic_]getauxval and stops
routing the KernelArgumentBlock address through the libc init functions.

Bug: none
Test: bionic unit tests
Change-Id: I96c7b02c21d55c454558b7a5a9243c682782f2dd
Merged-In: I96c7b02c21d55c454558b7a5a9243c682782f2dd
(cherry picked from commit 746ad15912cfa82271424747e94d8125acc43d8c)
diff --git a/libc/arch-x86/bionic/__libc_init_sysinfo.cpp b/libc/arch-x86/bionic/__libc_init_sysinfo.cpp
index 1bb7ab0..849d253 100644
--- a/libc/arch-x86/bionic/__libc_init_sysinfo.cpp
+++ b/libc/arch-x86/bionic/__libc_init_sysinfo.cpp
@@ -26,14 +26,15 @@
  * SUCH DAMAGE.
  */
 
-#include "private/KernelArgumentBlock.h"
+#include "private/bionic_auxv.h"
 #include "private/bionic_globals.h"
 
 // This file is compiled without stack protection, because it runs before TLS
 // has been set up.
 
-__LIBC_HIDDEN__ void __libc_init_sysinfo(KernelArgumentBlock& args) {
-  __libc_sysinfo = reinterpret_cast<void*>(args.getauxval(AT_SYSINFO));
+__LIBC_HIDDEN__ void __libc_init_sysinfo() {
+  bool dummy;
+  __libc_sysinfo = reinterpret_cast<void*>(__bionic_getauxval(AT_SYSINFO, dummy));
 }
 
 // TODO: lose this function and just access __libc_sysinfo directly.