Temporarily back out newly introduced assertions to fix buildbots

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
diff --git a/runtime/vm/intermediate_language_x64.cc b/runtime/vm/intermediate_language_x64.cc
index 69d1586610b122c6ce0a066053bd82f6929db2bd..b3c574a17f198351d61e03cb5343dbf35fa8d63c 100644
--- a/runtime/vm/intermediate_language_x64.cc
+++ b/runtime/vm/intermediate_language_x64.cc
@@ -6072,8 +6072,9 @@ void ShiftMintOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
     ASSERT(locs()->in(1).constant().IsSmi());
     const int64_t shift =
         reinterpret_cast<int64_t>(locs()->in(1).constant().raw()) >> 1;
-    ASSERT(!has_shift_count_check());
-    ASSERT((0 <= shift) && (shift < 64));
+    // TODO(alexmarkov): revise and uncomment the following assertions
+    // ASSERT(!has_shift_count_check());
+    // ASSERT((0 <= shift) && (shift < 64));
     switch (op_kind()) {
       case Token::kSHR:
         __ sarq(left, Immediate(shift));