ART: Change return types of field access entrypoints

Ensure that return types guarantee full-width data as the compiled
code and mterp expect by using size_t and ssize_t.

This fixes Clang no longer sign-/zero-extending small return types.

Bug: 30232671
Test: m ART_TEST_RUN_TEST_NDEBUG=true ART_TEST_INTERPRETER=true test-art-host-run-test
Change-Id: Ic505befc6c94e2dccbc8abf2b13d4c2d662e68d1
diff --git a/test/529-checker-unresolved/src/Main.java b/test/529-checker-unresolved/src/Main.java
index 5a36ba5..7b5cbc1 100644
--- a/test/529-checker-unresolved/src/Main.java
+++ b/test/529-checker-unresolved/src/Main.java
@@ -77,6 +77,16 @@
     expectEquals(123456789123456789f, UnresolvedClass.staticFloat);
     expectEquals(123456789123456789d, UnresolvedClass.staticDouble);
     expectEquals(o, UnresolvedClass.staticObject);
+
+    // Check "large" values.
+
+    UnresolvedClass.staticByte = (byte)-1;
+    UnresolvedClass.staticChar = (char)32768;
+    UnresolvedClass.staticInt = -1;
+
+    expectEquals((byte)-1, UnresolvedClass.staticByte);
+    expectEquals((char)32768, UnresolvedClass.staticChar);
+    expectEquals(-1, UnresolvedClass.staticInt);
   }
 
   /// CHECK-START: void Main.callUnresolvedInstanceFieldAccess(UnresolvedClass) register (before)