cppgc: IWYU cleanups

Used include-what-you-use [1] to clean up cppgc API headers. The tool
does somewhat work but requires some cleanup afterwards as it cannot
nicely deal with `v8config.h` and the defines it generates.

[1] https://github.com/include-what-you-use/include-what-you-use/

Bug: chromium:1056170
Change-Id: I7b03797c615f8e033510fc959bbdb792d8b7a4ee
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2907612Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74693}

include/cppgc/allocation.h

@@ -5,25 +5,20 @@
 #ifndef INCLUDE_CPPGC_ALLOCATION_H_
 #define INCLUDE_CPPGC_ALLOCATION_H_
 
-#include <stdint.h>
-
 #include <atomic>
+#include <cstddef>
+#include <cstdint>
+#include <new>
 #include <type_traits>
 
 #include "cppgc/custom-space.h"
-#include "cppgc/garbage-collected.h"
 #include "cppgc/internal/api-constants.h"
 #include "cppgc/internal/gc-info.h"
+#include "cppgc/type-traits.h"
+#include "v8config.h"  // NOLINT(build/include_directory)
 
 namespace cppgc {
 
-template <typename T>
-class MakeGarbageCollectedTraitBase;
-
-namespace internal {
-class ObjectAllocator;
-}  // namespace internal
-
 /**
  * AllocationHandle is used to allocate garbage-collected objects.
  */

include/cppgc/heap-statistics.h

@@ -5,7 +5,8 @@
 #ifndef INCLUDE_CPPGC_HEAP_STATISTICS_H_
 #define INCLUDE_CPPGC_HEAP_STATISTICS_H_
 
-#include <memory>
+#include <cstddef>
+#include <cstdint>
 #include <string>
 #include <vector>
 

include/cppgc/heap.h

@@ -5,6 +5,8 @@
 #ifndef INCLUDE_CPPGC_HEAP_H_
 #define INCLUDE_CPPGC_HEAP_H_
 
+#include <cstddef>
+#include <cstdint>
 #include <memory>
 #include <vector>
 

include/cppgc/internal/api-constants.h

@@ -5,8 +5,8 @@
 #ifndef INCLUDE_CPPGC_INTERNAL_API_CONSTANTS_H_
 #define INCLUDE_CPPGC_INTERNAL_API_CONSTANTS_H_
 
-#include <stddef.h>
-#include <stdint.h>
+#include <cstddef>
+#include <cstdint>
 
 #include "v8config.h"  // NOLINT(build/include_directory)
 

include/cppgc/internal/gc-info.h

@@ -7,6 +7,7 @@
 
 #include <atomic>
 #include <cstdint>
+#include <type_traits>
 
 #include "cppgc/internal/finalizer-trait.h"
 #include "cppgc/internal/name-trait.h"

include/cppgc/internal/write-barrier.h

@@ -5,6 +5,9 @@
 #ifndef INCLUDE_CPPGC_INTERNAL_WRITE_BARRIER_H_
 #define INCLUDE_CPPGC_INTERNAL_WRITE_BARRIER_H_
 
+#include <cstddef>
+#include <cstdint>
+
 #include "cppgc/heap-state.h"
 #include "cppgc/internal/api-constants.h"
 #include "cppgc/internal/atomic-entry-flag.h"
@@ -22,8 +25,11 @@ class HeapHandle;
 
 namespace internal {
 
+#if defined(CPPGC_CAGED_HEAP)
 class WriteBarrierTypeForCagedHeapPolicy;
+#else   // !CPPGC_CAGED_HEAP
 class WriteBarrierTypeForNonCagedHeapPolicy;
+#endif  // !CPPGC_CAGED_HEAP
 
 class V8_EXPORT WriteBarrier final {
  public:

include/cppgc/macros.h

@@ -5,7 +5,7 @@
 #ifndef INCLUDE_CPPGC_MACROS_H_
 #define INCLUDE_CPPGC_MACROS_H_
 
-#include <stddef.h>
+#include <cstddef>
 
 #include "cppgc/internal/compiler-specific.h"
 

include/cppgc/platform.h

@@ -5,6 +5,8 @@
 #ifndef INCLUDE_CPPGC_PLATFORM_H_
 #define INCLUDE_CPPGC_PLATFORM_H_
 
+#include <memory>
+
 #include "v8-platform.h"  // NOLINT(build/include_directory)
 #include "v8config.h"     // NOLINT(build/include_directory)
 

include/cppgc/source-location.h

@@ -5,6 +5,7 @@
 #ifndef INCLUDE_CPPGC_SOURCE_LOCATION_H_
 #define INCLUDE_CPPGC_SOURCE_LOCATION_H_
 
+#include <cstddef>
 #include <string>
 
 #include "v8config.h"  // NOLINT(build/include_directory)

src/heap/cppgc/allocation.cc

@@ -4,8 +4,9 @@
 
 #include "include/cppgc/allocation.h"
 
-#include "src/base/logging.h"
+#include "include/cppgc/internal/api-constants.h"
 #include "src/base/macros.h"
+#include "src/heap/cppgc/globals.h"
 #include "src/heap/cppgc/object-allocator.h"
 
 namespace cppgc {

src/heap/cppgc/object-allocator.h

@@ -18,6 +18,10 @@
 
 namespace cppgc {
 
+namespace internal {
+class ObjectAllocator;
+}  // namespace internal
+
 class V8_EXPORT AllocationHandle {
  private:
   AllocationHandle() = default;