Add tests for Thumb2RelativePatcher.

Also make the thumb2/arm64 thunk allocation precise instead
of eagerly allocating thunk space. This allows the calls to
use the maximum positive offset.

Change-Id: Ifa95b0bb00bd73eeab0c2905d21e2f3078f4b0a8
diff --git a/compiler/linker/relative_patcher.cc b/compiler/linker/relative_patcher.cc
index ed82ac2..71f38b4 100644
--- a/compiler/linker/relative_patcher.cc
+++ b/compiler/linker/relative_patcher.cc
@@ -33,7 +33,8 @@
     RelativePatcherNone() { }
 
     uint32_t ReserveSpace(uint32_t offset,
-                          const CompiledMethod* compiled_method ATTRIBUTE_UNUSED) OVERRIDE {
+                          const CompiledMethod* compiled_method ATTRIBUTE_UNUSED,
+                          MethodReference method_ref ATTRIBUTE_UNUSED) OVERRIDE {
       return offset;  // No space reserved; no patches expected.
     }