[cleanup] Remove dead {List} forward declaration.

R=petermarshall@chromium.org

Change-Id: I6901ddcd1ca1fda474e8d2766fbfc60d2f5a9bec
Reviewed-on: https://chromium-review.googlesource.com/763628Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49298}

src/globals.h

@@ -300,13 +300,6 @@ F FUNCTION_CAST(Address addr) {
 #endif
 
 
-// -----------------------------------------------------------------------------
-// Forward declarations for frequently used classes
-// (sorted alphabetically)
-
-class FreeStoreAllocationPolicy;
-template <typename T, class P = FreeStoreAllocationPolicy> class List;
-
 // -----------------------------------------------------------------------------
 // Declarations for use in both the preparser and the rest of V8.
 
@@ -468,11 +461,9 @@ const uint32_t kQuietNaNHighBitsMask = 0xfff << (51 - 32);
 // Forward declarations for frequently used classes
 
 class AccessorInfo;
-class Allocation;
 class Arguments;
 class Assembler;
 class Code;
-class CodeGenerator;
 class CodeStub;
 class Context;
 class Debug;
@@ -482,6 +473,7 @@ class DescriptorArray;
 class TransitionArray;
 class ExternalReference;
 class FixedArray;
+class FreeStoreAllocationPolicy;
 class FunctionTemplateInfo;
 class MemoryChunk;
 class NumberDictionary;