ART: Clean up arm64 kNumberOfXRegisters usage.

Avoid undefined behavior for arm64 stemming from 1u << 32 in
loops with upper bound kNumberOfXRegisters.

Create iterators for enumerating bits in an integer either
from high to low or from low to high and use them for
<arch>Context::FillCalleeSaves() on all architectures.

Refactor runtime/utils.{h,cc} by moving all bit-fiddling
functions to runtime/base/bit_utils.{h,cc} (together with
the new bit iterators) and all time-related functions to
runtime/base/time_utils.{h,cc}. Improve test coverage and
fix some corner cases for the bit-fiddling functions.

Bug: 13925192
Change-Id: I704884dab15b41ecf7a1c47d397ab1c3fc7ee0f7
diff --git a/runtime/mirror/array-inl.h b/runtime/mirror/array-inl.h
index 8b3418d..e93717e 100644
--- a/runtime/mirror/array-inl.h
+++ b/runtime/mirror/array-inl.h
@@ -19,11 +19,13 @@
 
 #include "array.h"
 
+#include "base/bit_utils.h"
+#include "base/logging.h"
 #include "base/stringprintf.h"
+#include "base/casts.h"
 #include "class.h"
 #include "gc/heap-inl.h"
 #include "thread.h"
-#include "utils.h"
 
 namespace art {
 namespace mirror {
diff --git a/runtime/mirror/art_method-inl.h b/runtime/mirror/art_method-inl.h
index 0f306e8..7c8067a 100644
--- a/runtime/mirror/art_method-inl.h
+++ b/runtime/mirror/art_method-inl.h
@@ -31,6 +31,7 @@
 #include "quick/quick_method_frame_info.h"
 #include "read_barrier-inl.h"
 #include "runtime-inl.h"
+#include "utils.h"
 
 namespace art {
 namespace mirror {
diff --git a/runtime/mirror/class-inl.h b/runtime/mirror/class-inl.h
index cc6f5c4..5752a15 100644
--- a/runtime/mirror/class-inl.h
+++ b/runtime/mirror/class-inl.h
@@ -32,6 +32,7 @@
 #include "reference-inl.h"
 #include "runtime.h"
 #include "string.h"
+#include "utils.h"
 
 namespace art {
 namespace mirror {
diff --git a/runtime/mirror/class.h b/runtime/mirror/class.h
index d3cfd01..b99fc68 100644
--- a/runtime/mirror/class.h
+++ b/runtime/mirror/class.h
@@ -27,7 +27,6 @@
 #include "object_callbacks.h"
 #include "primitive.h"
 #include "read_barrier_option.h"
-#include "utils.h"
 
 #ifndef IMT_SIZE
 #error IMT_SIZE not defined
diff --git a/runtime/mirror/object_array-inl.h b/runtime/mirror/object_array-inl.h
index d473816..bef4af6 100644
--- a/runtime/mirror/object_array-inl.h
+++ b/runtime/mirror/object_array-inl.h
@@ -17,6 +17,8 @@
 #ifndef ART_RUNTIME_MIRROR_OBJECT_ARRAY_INL_H_
 #define ART_RUNTIME_MIRROR_OBJECT_ARRAY_INL_H_
 
+#include <string>
+
 #include "object_array.h"
 
 #include "array-inl.h"
@@ -26,7 +28,7 @@
 #include "runtime.h"
 #include "handle_scope-inl.h"
 #include "thread.h"
-#include <string>
+#include "utils.h"
 
 namespace art {
 namespace mirror {
diff --git a/runtime/mirror/string-inl.h b/runtime/mirror/string-inl.h
index cd5d2f6..35b8aef 100644
--- a/runtime/mirror/string-inl.h
+++ b/runtime/mirror/string-inl.h
@@ -25,6 +25,7 @@
 #include "string.h"
 #include "thread.h"
 #include "utf.h"
+#include "utils.h"
 
 namespace art {
 namespace mirror {