[turbofan] Add FixedArray peephole optimizations to CodeStubAssembler

src/compiler/code-assembler.cc

Index: src/compiler/code-assembler.cc
diff --git a/src/compiler/code-assembler.cc b/src/compiler/code-assembler.cc
index 0a90b9e9251130c1b5fe1d872aa9d3d24f73ef8d..c47d3de6aaab82f9012e1c6d43d4b965c0bc73e7 100644
--- a/src/compiler/code-assembler.cc
+++ b/src/compiler/code-assembler.cc
@@ -10,6 +10,7 @@
 #include "src/compiler/graph.h"
 #include "src/compiler/instruction-selector.h"
 #include "src/compiler/linkage.h"
+#include "src/compiler/node-matchers.h"
 #include "src/compiler/pipeline.h"
 #include "src/compiler/raw-machine-assembler.h"
 #include "src/compiler/schedule.h"
@@ -87,10 +88,14 @@ bool CodeAssembler::IsFloat64RoundTruncateSupported() const {
   return raw_assembler_->machine()->Float64RoundTruncate().IsSupported();
 }
 
-Node* CodeAssembler::Int32Constant(int value) {
+Node* CodeAssembler::Int32Constant(int32_t value) {
   return raw_assembler_->Int32Constant(value);
 }
 
+Node* CodeAssembler::Int64Constant(int64_t value) {
+  return raw_assembler_->Int64Constant(value);
+}
+
 Node* CodeAssembler::IntPtrConstant(intptr_t value) {
   return raw_assembler_->IntPtrConstant(value);
 }
@@ -123,6 +128,36 @@ Node* CodeAssembler::NaNConstant() {
   return LoadRoot(Heap::kNanValueRootIndex);
 }
 
+bool CodeAssembler::ToInt32Constant(Node* node, int32_t& out_value) {
+  Int32Matcher m32(node);
+  if (m32.HasValue()) {
+    out_value = m32.Value();
+    return true;
+  }
+
+  Int64Matcher m64(node);
+  if (m64.HasValue() &&
+      m64.IsInRange(std::numeric_limits<int32_t>::min(),
+                    std::numeric_limits<int32_t>::max())) {
+    out_value = static_cast<int32_t>(m64.Value());
+    return true;
+  }
+
+  return false;
+}
+
+bool CodeAssembler::ToInt64Constant(Node* node, int64_t& out_value) {
+  Int64Matcher m(node);
+  if (m.HasValue()) out_value = m.Value();
+  return m.HasValue();
+}
+
+bool CodeAssembler::ToIntPtrConstant(Node* node, intptr_t& out_value) {
+  IntPtrMatcher m(node);
+  if (m.HasValue()) out_value = m.Value();
+  return m.HasValue();
+}
+
 Node* CodeAssembler::Parameter(int value) {
   return raw_assembler_->Parameter(value);
 }