Add appropriate casts for char16_t.

C++11 defines a real char16_t, which is not implicitly convertible to
uint16_t (and by extension jchar). Add casts as needed.

Bug: 18300613
Change-Id: I00752002ef2e938bdb57f70947e8fd53ec103293
diff --git a/libs/hwui/TextDropShadowCache.cpp b/libs/hwui/TextDropShadowCache.cpp
index 4eec462..96c09e6 100644
--- a/libs/hwui/TextDropShadowCache.cpp
+++ b/libs/hwui/TextDropShadowCache.cpp
@@ -40,7 +40,8 @@
     hash = JenkinsHashMix(hash, android::hash_type(italicStyle));
     hash = JenkinsHashMix(hash, android::hash_type(scaleX));
     if (text) {
-        hash = JenkinsHashMixShorts(hash, text, charCount);
+        hash = JenkinsHashMixShorts(
+            hash, reinterpret_cast<const uint16_t*>(text), charCount);
     }
     if (positions) {
         for (uint32_t i = 0; i < charCount * 2; i++) {