ART: Fix sharpening across dex files

Bug: 15196336
Change-Id: If4301bcddce0ddbc60bb33403e4a76eed35bcb2f
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 3304561..8d4e283 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -1135,7 +1135,7 @@
       if (dex_method_idx != DexFile::kDexNoIndex) {
         target_method->dex_method_index = dex_method_idx;
       } else {
-        if (compiling_boot) {
+        if (compiling_boot && !use_dex_cache) {
           target_method->dex_method_index = method->GetDexMethodIndex();
           target_method->dex_file = method->GetDeclaringClass()->GetDexCache()->GetDexFile();
         }