Serialize `#pragma comment`.

`#pragma comment` was handled by Sema calling a function on ASTConsumer, and
CodeGen then implementing this function and writing things to its output.

Instead, introduce a PragmaCommentDecl AST node and hang one off the
TranslationUnitDecl for every `#pragma comment` line, and then use the regular
serialization machinery. (Since PragmaCommentDecl has codegen relevance, it's
eagerly deserialized.)

http://reviews.llvm.org/D17799

llvm-svn: 262493
diff --git a/clang/lib/CodeGen/ModuleBuilder.cpp b/clang/lib/CodeGen/ModuleBuilder.cpp
index 234a773..968cc46 100644
--- a/clang/lib/CodeGen/ModuleBuilder.cpp
+++ b/clang/lib/CodeGen/ModuleBuilder.cpp
@@ -104,9 +104,9 @@
                                                *M, Diags, CoverageInfo));
 
       for (auto &&Lib : CodeGenOpts.DependentLibraries)
-        HandleDependentLibrary(Lib);
+        Builder->AddDependentLib(Lib);
       for (auto &&Opt : CodeGenOpts.LinkerOptions)
-        HandleLinkerOption(Opt);
+        Builder->AppendLinkerOptions(Opt);
     }
 
     void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) override {
@@ -234,18 +234,10 @@
       Builder->EmitVTable(RD);
     }
 
-    void HandleLinkerOption(llvm::StringRef Opts) override {
-      Builder->AppendLinkerOptions(Opts);
-    }
-
     void HandleDetectMismatch(llvm::StringRef Name,
                               llvm::StringRef Value) override {
       Builder->AddDetectMismatch(Name, Value);
     }
-
-    void HandleDependentLibrary(llvm::StringRef Lib) override {
-      Builder->AddDependentLib(Lib);
-    }
   };
 }