Build CodeSourceMap for each code object

runtime/vm/flow_graph_compiler_x64.cc

Index: runtime/vm/flow_graph_compiler_x64.cc
diff --git a/runtime/vm/flow_graph_compiler_x64.cc b/runtime/vm/flow_graph_compiler_x64.cc
index 49aeed86e43b1dd212492df1dacef92efb924f22..e6b9c0f5059f80999d3d32031fab74c2e4b6b50a 100644
--- a/runtime/vm/flow_graph_compiler_x64.cc
+++ b/runtime/vm/flow_graph_compiler_x64.cc
@@ -1137,6 +1137,7 @@ void FlowGraphCompiler::CompileGraph() {
     }
   }
 
+  MaybeEmitCodeSourceMapEntry(TokenPosition::kDartCodePrologue);
   ASSERT(!block_order().is_empty());
   VisitBlocks();
 
@@ -1146,6 +1147,7 @@ void FlowGraphCompiler::CompileGraph() {
   // Emit function patching code. This will be swapped with the first 13 bytes
   // at entry point.
 
+  SaveCodeSize();
   if (is_optimizing() && !FLAG_precompilation) {
     // Leave enough space for patching in case of lazy deoptimization from
     // deferred code.
@@ -1153,6 +1155,7 @@ void FlowGraphCompiler::CompileGraph() {
     lazy_deopt_pc_offset_ = assembler()->CodeSize();
     __ Jmp(*StubCode::DeoptimizeLazy_entry(), PP);
   }
+  MaybeEmitCodeSourceMapEntry(TokenPosition::kDartCodeEpilogue);
 }