Add runOnModuleCode helper. NFC (#4234)

This method is in parallel to runOnFunction above it. It sets the runner
and then does the walk, like that method.

Also set runner to nullptr by default. I noticed ubsan was warning on
things here, which this should avoid, but otherwise I'm not aware of an
actual bug, so this should be NFC. But it does provide a safer API
that should avoid future bugs.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/passes/ConstantFieldPropagation.cpp b/src/passes/ConstantFieldPropagation.cpp
index 0894a822a..2fdd8333c 100644
--- a/src/passes/ConstantFieldPropagation.cpp
+++ b/src/passes/ConstantFieldPropagation.cpp
@@ -274,7 +274,7 @@ struct ConstantFieldPropagation : public Pass {
       functionSetInfos(*module);
     PCVScanner scanner(functionNewInfos, functionSetInfos);
     scanner.run(runner, module);
-    scanner.walkModuleCode(module);
+    scanner.runOnModuleCode(runner, module);
 
     // Combine the data from the functions.
     PCVStructValuesMap combinedNewInfos, combinedSetInfos;