[clang-tidy] Use explicit default

The constructor of AbstractState isn't doing anything interesting, so
can be removed.

See
https://chromium.googlesource.com/chromium/src/+/HEAD/styleguide/c++/c++-dos-and-donts.md#prefer-to-use.

Bug: v8:10488
Change-Id: If413a69aa83689f55a51e48179b75287a4620d5e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2233857Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68272}

src/compiler/load-elimination.h

@@ -228,8 +228,6 @@ class V8_EXPORT_PRIVATE LoadElimination final
 
   class AbstractState final : public ZoneObject {
    public:
-    AbstractState() {}
-
     bool Equals(AbstractState const* that) const;
     void Merge(AbstractState const* that, Zone* zone);
 

src/compiler/pipeline.cc

@@ -1020,7 +1020,7 @@ PipelineCompilationJob::PipelineCompilationJob(
   compilation_info_.SetOptimizingForOsr(osr_offset, osr_frame);
 }
 
-PipelineCompilationJob::~PipelineCompilationJob() {}
+PipelineCompilationJob::~PipelineCompilationJob() = default;
 
 namespace {
 // Ensure that the RuntimeStats table is set on the PipelineData for