Fuzzer: Better fuzzing of globals (#6611)

With this PR we generate global.gets in globals, which we did not do before.
We do that by replacing makeConst (the only thing we did before, for the
contents of globals) with makeTrivial, and add code to makeTrivial to sometimes
make a global.get. When no suitable global exists, makeGlobalGet will emit a
constant, so there is no danger in trying.

Also raise the number of globals a little.

Also explicitly note the current limitation of requiring all tuple globals to contain
tuple.make and nothing else, including not global.get, and avoid adding such
invalid global.gets in tuple globals in the fuzzer.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/tools/fuzzing.h b/src/tools/fuzzing.h
index 786527236..75e3a2a9a 100644
--- a/src/tools/fuzzing.h
+++ b/src/tools/fuzzing.h
@@ -106,6 +106,8 @@ private:
 
   std::unordered_map<Type, std::vector<Name>> globalsByType;
   std::unordered_map<Type, std::vector<Name>> mutableGlobalsByType;
+  std::unordered_map<Type, std::vector<Name>> immutableGlobalsByType;
+  std::unordered_map<Type, std::vector<Name>> importedImmutableGlobalsByType;
 
   std::vector<Type> loggableTypes;