[PDB] Enable NativeSession to create symbols for built-in types on demand

Summary:
There is a reserved range of type indexes for built-in types (like integers).
This will create a symbol for a built-in type if the caller askes for one by
type index.  This is also plumbing for being able to recall symbols by type
index in general, but user-defined types will come in subsequent patches.

Reviewers: rnk, zturner

Subscribers: mgorny, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D35163

llvm-svn: 307834
diff --git a/llvm/lib/DebugInfo/PDB/Native/NativeExeSymbol.cpp b/llvm/lib/DebugInfo/PDB/Native/NativeExeSymbol.cpp
index 6206155..cb0830f 100644
--- a/llvm/lib/DebugInfo/PDB/Native/NativeExeSymbol.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/NativeExeSymbol.cpp
@@ -18,7 +18,7 @@
 namespace llvm {
 namespace pdb {
 
-NativeExeSymbol::NativeExeSymbol(NativeSession &Session, uint32_t SymbolId)
+NativeExeSymbol::NativeExeSymbol(NativeSession &Session, SymIndexId SymbolId)
     : NativeRawSymbol(Session, SymbolId), File(Session.getPDBFile()) {}
 
 std::unique_ptr<NativeRawSymbol> NativeExeSymbol::clone() const {