Reland "[Compiler] Remove CompileDebugCode and EnsureBytecode and replace with Compile"

This is a reland of 21da12a
Original change's description:
> [Compiler] Remove CompileDebugCode and EnsureBytecode and replace with Compile
> 
> Removes the Compiler::CompileDebugCode and Compiler::EnsureBytecode functions
> and replaces them with a Compiler::Compile(Handle<SharedFunctionInfo> shared)
> function. The code in compiler.cc is refactored to use this function to compile
> the SharedFunctionInfo when compiling a JSFunction.
> 
> Also does some other cleanup:
>  - Removes CompileUnoptimizedFunction and inlines into new Compiler function
>  - Moves code to create top level SharedFunctionInfo into CompilerTopLevel and
>    out of FinalizeUnoptimizedCompile.
> 
> BUG=v8:6409
> 
> Change-Id: Ic54afcd8eb005c17f3ae6b2355060846e3091ca3
> Reviewed-on: https://chromium-review.googlesource.com/613760
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#47394}

TBR=yangguo@chromium.org
TBR=jarin@chromium.org

Bug: v8:6409
Change-Id: If2eae66a85f129e746a5ca5c04935540f3f86b04
Reviewed-on: https://chromium-review.googlesource.com/618886
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47399}

Author: rmcilroy

src/compilation-info.cc

@@ -30,7 +30,6 @@ CompilationInfo::CompilationInfo(Zone* zone, Isolate* isolate,
   literal_ = literal;
   source_range_map_ = parse_info->source_range_map();
 
-  if (parse_info->is_debug()) MarkAsDebug();
   if (parse_info->is_eval()) MarkAsEval();
   if (parse_info->is_native()) MarkAsNative();
   if (parse_info->will_serialize()) MarkAsSerializing();

src/compilation-info.h

@@ -36,18 +36,17 @@ class V8_EXPORT_PRIVATE CompilationInfo final {
   // Various configuration flags for a compilation, as well as some properties
   // of the compiled code produced by a compilation.
   enum Flag {
-    kIsDebug = 1 << 0,
-    kIsEval = 1 << 1,
-    kIsNative = 1 << 2,
-    kSerializing = 1 << 3,
-    kAccessorInliningEnabled = 1 << 4,
-    kFunctionContextSpecializing = 1 << 5,
-    kInliningEnabled = 1 << 6,
-    kDisableFutureOptimization = 1 << 7,
-    kSplittingEnabled = 1 << 8,
-    kSourcePositionsEnabled = 1 << 9,
-    kBailoutOnUninitialized = 1 << 10,
-    kLoopPeelingEnabled = 1 << 11,
+    kIsEval = 1 << 0,
+    kIsNative = 1 << 1,
+    kSerializing = 1 << 2,
+    kAccessorInliningEnabled = 1 << 3,
+    kFunctionContextSpecializing = 1 << 4,
+    kInliningEnabled = 1 << 5,
+    kDisableFutureOptimization = 1 << 6,
+    kSplittingEnabled = 1 << 7,
+    kSourcePositionsEnabled = 1 << 8,
+    kBailoutOnUninitialized = 1 << 9,
+    kLoopPeelingEnabled = 1 << 10,
   };
 
   // Construct a compilation info for unoptimized compilation.
@@ -108,11 +107,6 @@ class V8_EXPORT_PRIVATE CompilationInfo final {
 
   // Flags used by unoptimized compilation.
 
-  // Compiles marked as debug produce unoptimized code with debug break slots.
-  // Inner functions that cannot be compiled w/o context are compiled eagerly.
-  void MarkAsDebug() { SetFlag(kIsDebug); }
-  bool is_debug() const { return GetFlag(kIsDebug); }
-
   void MarkAsSerializing() { SetFlag(kSerializing); }
   bool will_serialize() const { return GetFlag(kSerializing); }
 
@@ -161,7 +155,7 @@ class V8_EXPORT_PRIVATE CompilationInfo final {
     // Generate a pre-aged prologue if we are optimizing for size, which
     // will make code old more aggressive. Only apply to Code::FUNCTION,
     // since only functions are aged in the compilation cache.
-    return FLAG_optimize_for_size && FLAG_age_code && !is_debug() &&
+    return FLAG_optimize_for_size && FLAG_age_code &&
            output_code_kind() == Code::FUNCTION;
   }