[iwyu] Minor iwyu fixes.

BUG=v8:5294

Review-Url: https://codereview.chromium.org/2662393004
Cr-Commit-Position: refs/heads/master@{#42857}

src/ast/modules.cc

@@ -7,6 +7,7 @@
 #include "src/ast/scopes.h"
 #include "src/objects-inl.h"
 #include "src/objects/module-info.h"
+#include "src/pending-compilation-error-handler.h"
 
 namespace v8 {
 namespace internal {

src/ast/modules.h

@@ -6,7 +6,6 @@
 #define V8_AST_MODULES_H_
 
 #include "src/parsing/scanner.h"  // Only for Scanner::Location.
-#include "src/pending-compilation-error-handler.h"
 #include "src/zone/zone-containers.h"
 
 namespace v8 {
@@ -16,6 +15,7 @@ namespace internal {
 class AstRawString;
 class ModuleInfo;
 class ModuleInfoEntry;
+class PendingCompilationErrorHandler;
 
 class ModuleDescriptor : public ZoneObject {
  public:

src/parsing/preparser.h

@@ -9,6 +9,7 @@
 #include "src/ast/scopes.h"
 #include "src/parsing/parser-base.h"
 #include "src/parsing/preparse-data.h"
+#include "src/pending-compilation-error-handler.h"
 
 namespace v8 {
 namespace internal {