[mpact] bump torch-mlir to @b3942ff984cdb44e3f (#74)

diff --git a/externals/torch-mlir b/externals/torch-mlir
index b92e618..b3942ff 160000
--- a/externals/torch-mlir
+++ b/externals/torch-mlir
@@ -1 +1 @@
-Subproject commit b92e61832f85f35ec36bb0c168bd5e022c1169dc
+Subproject commit b3942ff984cdb44e3f5e17194632d0bfc6a613cc