ast: Rename UnaryOp::kDereference to kIndirection

This is what it is (currently) called in the spec

Bug: tint:727
Change-Id: Ie24f42499ed20c0c45ef4e9474bc6bb6a19bfa36
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/51181
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: David Neto <dneto@google.com>

src/ast/unary_op.cc

@@ -23,8 +23,8 @@ std::ostream& operator<<(std::ostream& out, UnaryOp mod) {
       out << "address-of";
       break;
     }
-    case UnaryOp::kDereference: {
-      out << "dereference";
+    case UnaryOp::kIndirection: {
+      out << "indirection";
       break;
     }
     case UnaryOp::kNegation: {

src/ast/unary_op.h

@@ -23,7 +23,7 @@ namespace ast {
 /// The unary op
 enum class UnaryOp {
   kAddressOf,    // &EXPR
-  kDereference,  // *EXPR
+  kIndirection,  // *EXPR
   kNegation,     // -EXPR
   kNot,          // !EXPR
 };