fix: restore getauxval_fix.c + current_thread tokio — both needed

The getauxval override (dlsym wrapper) fixes SIGSEGV in
init_have_lse_atomics at library load time. The current_thread
tokio runtime avoids SEGV_ACCERR in pthread_create/__init_tcb.
Both fixes are required together.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/wzp-android/build.rs

@@ -4,6 +4,12 @@ fn main() {
     let target = std::env::var("TARGET").unwrap_or_default();
 
     if target.contains("android") {
+        // Override broken static getauxval from compiler-rt that crashes
+        // in shared libraries. Must be compiled first to take link priority.
+        cc::Build::new()
+            .file("cpp/getauxval_fix.c")
+            .compile("getauxval_fix");
+
         let oboe_dir = fetch_oboe();
         match oboe_dir {
             Some(oboe_path) => {

crates/wzp-android/cpp/getauxval_fix.c

@@ -0,0 +1,21 @@
+// Override the broken static getauxval from compiler-rt/CRT.
+// The static version reads from __libc_auxv which is NULL in shared libs
+// loaded via dlopen, causing SIGSEGV in init_have_lse_atomics at load time.
+// This version calls the real bionic getauxval via dlsym.
+#ifdef __ANDROID__
+#include <dlfcn.h>
+#include <stdint.h>
+
+typedef unsigned long (*getauxval_fn)(unsigned long);
+
+unsigned long getauxval(unsigned long type) {
+    static getauxval_fn real_getauxval = (getauxval_fn)0;
+    if (!real_getauxval) {
+        real_getauxval = (getauxval_fn)dlsym((void*)-1L /* RTLD_DEFAULT */, "getauxval");
+        if (!real_getauxval) {
+            return 0;
+        }
+    }
+    return real_getauxval(type);
+}
+#endif