[WinEH] Start inserting state number stores for C++ EH

This moves all the state numbering code for C++ EH to WinEHPrepare so
that we can call it from the X86 state numbering IR pass that runs
before isel.

Now we just call the same state numbering machinery and insert a bunch
of stores. It also populates MachineModuleInfo with information about
the current function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238514 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/WinEHFuncInfo.h

@@ -23,6 +23,7 @@ class BasicBlock;
 class Constant;
 class Function;
 class GlobalVariable;
+class InvokeInst;
 class IntrinsicInst;
 class LandingPadInst;
 class MCSymbol;
@@ -153,5 +154,11 @@ struct WinEHFuncInfo {
         NumIPToStateFuncsVisited(0) {}
 };
 
+/// Analyze the IR in ParentFn and it's handlers to build WinEHFuncInfo, which
+/// describes the state numbers and tables used by __CxxFrameHandler3. This
+/// analysis assumes that WinEHPrepare has already been run.
+void calculateWinCXXEHStateNumbers(const Function *ParentFn,
+                                   WinEHFuncInfo &FuncInfo);
+
 }
 #endif // LLVM_CODEGEN_WINEHFUNCINFO_H