Make enabling of CSA verifier a build-time flag

src/compiler/raw-machine-assembler.h

Index: src/compiler/raw-machine-assembler.h
diff --git a/src/compiler/raw-machine-assembler.h b/src/compiler/raw-machine-assembler.h
index af36b8c08ac8b4a8758118597b672d6a3bec8b5f..3ed932ee10c3b1a26d4787e891f5d0b4e20860d0 100644
--- a/src/compiler/raw-machine-assembler.h
+++ b/src/compiler/raw-machine-assembler.h
@@ -534,13 +534,21 @@ class V8_EXPORT_PRIVATE RawMachineAssembler {
 
   // Conversions.
   Node* BitcastTaggedToWord(Node* a) {
+#ifdef ENABLE_VERIFY_CSA
     return AddNode(machine()->BitcastTaggedToWord(), a);
+#else
+    return a;
+#endif
   }
   Node* BitcastWordToTagged(Node* a) {
     return AddNode(machine()->BitcastWordToTagged(), a);
   }
   Node* BitcastWordToTaggedSigned(Node* a) {
+#ifdef ENABLE_VERIFY_CSA
     return AddNode(machine()->BitcastWordToTaggedSigned(), a);
+#else
+    return a;
+#endif
   }
   Node* TruncateFloat64ToWord32(Node* a) {
     return AddNode(machine()->TruncateFloat64ToWord32(), a);