[Docs] Update ExceptionHandling example (NFC)

Fix some syntax errors and use opaque pointers.

Author: nikic

llvm/docs/ExceptionHandling.rst

@@ -601,19 +601,19 @@ all of the new IR instructions:
 
 .. code-block:: text
 
-  define i32 @f() nounwind personality i32 (...)* @__CxxFrameHandler3 {
+  define i32 @f() nounwind personality ptr @__CxxFrameHandler3 {
   entry:
     %obj = alloca %struct.Cleanup, align 4
     %e = alloca i32, align 4
-    %call = invoke %struct.Cleanup* @"??0Cleanup@@QEAA@XZ"(%struct.Cleanup* nonnull %obj)
+    %call = invoke ptr @"??0Cleanup@@QEAA@XZ"(ptr nonnull %obj)
             to label %invoke.cont unwind label %lpad.catch
 
   invoke.cont:                                      ; preds = %entry
     invoke void @"?may_throw@@YAXXZ"()
             to label %invoke.cont.2 unwind label %lpad.cleanup
 
   invoke.cont.2:                                    ; preds = %invoke.cont
-    call void @"??_DCleanup@@QEAA@XZ"(%struct.Cleanup* nonnull %obj) nounwind
+    call void @"??_DCleanup@@QEAA@XZ"(ptr nonnull %obj) nounwind
     br label %return
 
   return:                                           ; preds = %invoke.cont.3, %invoke.cont.2
@@ -622,24 +622,24 @@ all of the new IR instructions:
 
   lpad.cleanup:                                     ; preds = %invoke.cont.2
     %0 = cleanuppad within none []
-    call void @"??1Cleanup@@QEAA@XZ"(%struct.Cleanup* nonnull %obj) nounwind
-    cleanupret %0 unwind label %lpad.catch
+    call void @"??1Cleanup@@QEAA@XZ"(ptr nonnull %obj) nounwind
+    cleanupret from %0 unwind label %lpad.catch
 
   lpad.catch:                                       ; preds = %lpad.cleanup, %entry
     %1 = catchswitch within none [label %catch.body] unwind label %lpad.terminate
 
   catch.body:                                       ; preds = %lpad.catch
-    %catch = catchpad within %1 [%rtti.TypeDescriptor2* @"??_R0H@8", i32 0, i32* %e]
+    %catch = catchpad within %1 [ptr @"??_R0H@8", i32 0, ptr %e]
     invoke void @"?may_throw@@YAXXZ"()
             to label %invoke.cont.3 unwind label %lpad.terminate
 
   invoke.cont.3:                                    ; preds = %catch.body
-    %3 = load i32, i32* %e, align 4
+    %3 = load i32, ptr %e, align 4
     catchret from %catch to label %return
 
   lpad.terminate:                                   ; preds = %catch.body, %lpad.catch
     cleanuppad within none []
-    call void @"?terminate@@YAXXZ"
+    call void @"?terminate@@YAXXZ"()
     unreachable
   }