Revert "Implement Dot Product Vectorization for x86"

This reverts commit 4b7caeee57767f6bce7bb138a1299c0ae84bebf9.

Reason for revert: Test failure in jit-gcstress mode.
+Exception in thread "main" java.lang.Error: Expected: 131072, found: 0
+ at other.TestCharShort.expectEquals(TestCharShort.java:474)
+ at other.TestCharShort.testDotProd(TestCharShort.java:486)
+ at other.TestCharShort.run(TestCharShort.java:525)
+ at Main.main(Main.java:28)

Change-Id: I251cf666e8335499d227910987b2d49629c3f53d
diff --git a/compiler/optimizing/loop_optimization.cc b/compiler/optimizing/loop_optimization.cc
index 567a41e..9c4e9d2 100644
--- a/compiler/optimizing/loop_optimization.cc
+++ b/compiler/optimizing/loop_optimization.cc
@@ -1623,19 +1623,13 @@
                              kNoDotProd;
             return TrySetVectorLength(16);
           case DataType::Type::kUint16:
-            *restrictions |= kNoDiv |
-                             kNoAbs |
-                             kNoSignedHAdd |
-                             kNoUnroundedHAdd |
-                             kNoSAD |
-                             kNoDotProd;
-            return TrySetVectorLength(8);
           case DataType::Type::kInt16:
             *restrictions |= kNoDiv |
                              kNoAbs |
                              kNoSignedHAdd |
                              kNoUnroundedHAdd |
-                             kNoSAD;
+                             kNoSAD|
+                             kNoDotProd;
             return TrySetVectorLength(8);
           case DataType::Type::kInt32:
             *restrictions |= kNoDiv | kNoSAD;
@@ -2172,7 +2166,7 @@
                                               bool generate_code,
                                               DataType::Type reduction_type,
                                               uint64_t restrictions) {
-  if (!instruction->IsAdd() || reduction_type != DataType::Type::kInt32) {
+  if (!instruction->IsAdd() || (reduction_type != DataType::Type::kInt32)) {
     return false;
   }