Update doc comments to match new enum structure.

Change-Id: I5b4fe40847112a11d6057ee7acd208879a71722f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/319190
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

src/sksl/ir/SkSLExpression.h

@@ -73,7 +73,7 @@ struct Expression : public IRNode {
 
     /**
      *  Use is<T> to check the type of an expression.
-     *  e.g. replace `e.fKind == Expression::kIntLiteral_Kind` with `e.is<IntLiteral>()`.
+     *  e.g. replace `e.kind() == Expression::Kind::kIntLiteral` with `e.is<IntLiteral>()`.
      */
     template <typename T>
     bool is() const {

src/sksl/ir/SkSLProgramElement.h

@@ -42,7 +42,7 @@ struct ProgramElement : public IRNode {
 
     /**
      *  Use is<T> to check the type of a program element.
-     *  e.g. replace `el.fKind == ProgramElement::kEnum_Kind` with `el.is<Enum>()`.
+     *  e.g. replace `el.kind() == ProgramElement::Kind::kEnum` with `el.is<Enum>()`.
      */
     template <typename T>
     bool is() const {

src/sksl/ir/SkSLStatement.h

@@ -50,7 +50,7 @@ struct Statement : public IRNode {
 
     /**
      *  Use is<T> to check the type of a statement.
-     *  e.g. replace `s.fKind == Statement::kReturn_Kind` with `s.is<ReturnStatement>()`.
+     *  e.g. replace `s.kind() == Statement::Kind::kReturn` with `s.is<ReturnStatement>()`.
      */
     template <typename T>
     bool is() const {

src/sksl/ir/SkSLSymbol.h

@@ -46,7 +46,7 @@ struct Symbol : public IRNode {
 
     /**
      *  Use is<T> to check the type of a symbol.
-     *  e.g. replace `sym.fKind == Symbol::kVariable_Kind` with `sym.is<Variable>()`.
+     *  e.g. replace `sym.kind() == Symbol::Kind::kVariable` with `sym.is<Variable>()`.
      */
     template <typename T>
     bool is() const {