Give more precise types to some Math functions.

src/compiler/js-typed-lowering.cc

Index: src/compiler/js-typed-lowering.cc
diff --git a/src/compiler/js-typed-lowering.cc b/src/compiler/js-typed-lowering.cc
index be125342eaed0cc683322c7ccf19ecb3bc4bd79f..23fe36c3ba2f17c4300d2f8b1b7659a1d4270e61 100644
--- a/src/compiler/js-typed-lowering.cc
+++ b/src/compiler/js-typed-lowering.cc
@@ -163,7 +163,7 @@ class JSBinopReduction {
     return n;
   }
 
-  // Try to narrowing a double or number operation to an Int32 operation.
+  // Try narrowing a double or number operation to an Int32 operation.
   bool TryNarrowingToI32(Type* type, Node* node) {
     switch (node->opcode()) {
       case IrOpcode::kFloat64Add:
@@ -573,7 +573,7 @@ Reduction JSTypedLowering::ReduceJSStoreProperty(Node* node) {
   Type* base_type = NodeProperties::GetBounds(base).upper;
   // TODO(mstarzinger): This lowering is not correct if:
   //   a) The typed array turns external (i.e. MaterializeArrayBuffer)
-  //   b) The typed array or it's buffer is neutered.
+  //   b) The typed array or its buffer is neutered.
   if (key_type->Is(Type::Integral32()) && base_type->IsConstant() &&
       base_type->AsConstant()->Value()->IsJSTypedArray()) {
     // JSStoreProperty(typed-array, int32, value)