[compiler] Fix Turbolizer with StoreLane nodes

Turbolizer can fail to open traces that contain 'StoreLine' nodes.
There is a problem in operator<<(std::ostream& os, StoreLaneParameters
params) that prints StoreLaneParameters.laneidx as a char and not as
an integer, and this can cause the insertion of string terminators in
the trace json file.
This CL fixes the issue.

Change-Id: Icf7700660cca2b4068f61dafa0c8f485b1aa497a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3035362
Commit-Queue: Paolo Severini <paolosev@microsoft.com>
Reviewed-by: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75767}

src/compiler/machine-operator.cc

@@ -147,8 +147,8 @@ size_t hash_value(StoreLaneParameters params) {
 }
 
 std::ostream& operator<<(std::ostream& os, StoreLaneParameters params) {
-  return os << "(" << params.kind << " " << params.rep << " " << params.laneidx
-            << ")";
+  return os << "(" << params.kind << " " << params.rep << " "
+            << static_cast<unsigned int>(params.laneidx) << ")";
 }
 
 StoreLaneParameters const& StoreLaneParametersOf(Operator const* op) {