ART: Add string-alloc-inl.h

In an effort to reduce the (transitive) proliferation of heap-inl
add a specific inline header for string allocation.

Bug: 118385392
Test: mmma art
Test: m test-art-host
Change-Id: I68d3bcf2b3615d12231010940d0a24a1dbc03826
diff --git a/runtime/interpreter/interpreter_switch_impl-inl.h b/runtime/interpreter/interpreter_switch_impl-inl.h
index c430de2..b2ea862 100644
--- a/runtime/interpreter/interpreter_switch_impl-inl.h
+++ b/runtime/interpreter/interpreter_switch_impl-inl.h
@@ -27,6 +27,7 @@
 #include "interpreter_common.h"
 #include "jit/jit.h"
 #include "jvalue-inl.h"
+#include "mirror/string-alloc-inl.h"
 #include "nth_caller_visitor.h"
 #include "safe_math.h"
 #include "shadow_frame-inl.h"