Compressed native PC for stack maps

Compress native PC based on instruction alignment. This reduces the
size of stack maps, boot.oat is 0.4% smaller for arm64.

Test: test-art-host, test-art-target, N6P booting

Change-Id: I2b70eecabda88b06fa80a85688fd992070d54278
diff --git a/runtime/oat_quick_method_header.cc b/runtime/oat_quick_method_header.cc
index 9c2378d..fd84426 100644
--- a/runtime/oat_quick_method_header.cc
+++ b/runtime/oat_quick_method_header.cc
@@ -80,7 +80,7 @@
                                    : code_info.GetStackMapForDexPc(dex_pc, encoding);
   if (stack_map.IsValid()) {
     return reinterpret_cast<uintptr_t>(entry_point) +
-           stack_map.GetNativePcOffset(encoding.stack_map_encoding);
+           stack_map.GetNativePcOffset(encoding.stack_map_encoding, kRuntimeISA);
   }
   if (abort_on_failure) {
     ScopedObjectAccess soa(Thread::Current());