Add .clang-format and run clang-format on runtime/platform.

runtime/platform/utils.cc

Index: runtime/platform/utils.cc
diff --git a/runtime/platform/utils.cc b/runtime/platform/utils.cc
index 77783909495bac054683b8c50375059db699856b..0dde3c702713eee0fb8c6f92dadd07c425146878 100644
--- a/runtime/platform/utils.cc
+++ b/runtime/platform/utils.cc
@@ -39,11 +39,26 @@ int Utils::HighestBit(int64_t v) {
   uint64_t x = static_cast<uint64_t>((v > 0) ? v : -v);
   uint64_t t;
   int r = 0;
-  if ((t = x >> 32) != 0) { x = t; r += 32; }
-  if ((t = x >> 16) != 0) { x = t; r += 16; }
-  if ((t = x >> 8) != 0) { x = t; r += 8; }
-  if ((t = x >> 4) != 0) { x = t; r += 4; }
-  if ((t = x >> 2) != 0) { x = t; r += 2; }
+  if ((t = x >> 32) != 0) {
+    x = t;
+    r += 32;
+  }
+  if ((t = x >> 16) != 0) {
+    x = t;
+    r += 16;
+  }
+  if ((t = x >> 8) != 0) {
+    x = t;
+    r += 8;
+  }
+  if ((t = x >> 4) != 0) {
+    x = t;
+    r += 4;
+  }
+  if ((t = x >> 2) != 0) {
+    x = t;
+    r += 2;
+  }
   if (x > 1) r += 1;
   return r;
 }