Update NSPR to 4.12 and NSS to 3.23 on iOS

nspr/lib/ds/plarena.h

Index: nspr/lib/ds/plarena.h
diff --git a/nspr/lib/ds/plarena.h b/nspr/lib/ds/plarena.h
index 4daafa8cf51f07e8f151af7911c465076ccd9250..2673a2ae16667a63427e9a2ea343a07720281a07 100644
--- a/nspr/lib/ds/plarena.h
+++ b/nspr/lib/ds/plarena.h
@@ -96,11 +96,11 @@ struct PLArenaPool {
 
 /* These definitions are usually provided through the
  * sanitizer/asan_interface.h header installed by ASan.
- * See https://code.google.com/p/address-sanitizer/wiki/ManualPoisoning
+ * See https://github.com/google/sanitizers/wiki/AddressSanitizerManualPoisoning
  */
 
-void __asan_poison_memory_region(void const volatile *addr, size_t size);
-void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
+PR_IMPORT(void) __asan_poison_memory_region(void const volatile *addr, size_t size);
+PR_IMPORT(void) __asan_unpoison_memory_region(void const volatile *addr, size_t size);
 
 #define PL_MAKE_MEM_NOACCESS(addr, size) \
     __asan_poison_memory_region((addr), (size))