Fix materialization threshold too-large problem, assuming no long calls.

Change-Id: I6a7a99c366f336655c26bb39665a5d26e573374f
diff --git a/src/compiler_llvm/compilation_unit.h b/src/compiler_llvm/compilation_unit.h
index 18ecfa0..953f4f4 100644
--- a/src/compiler_llvm/compilation_unit.h
+++ b/src/compiler_llvm/compilation_unit.h
@@ -95,7 +95,7 @@
   }
 
   bool IsMaterializeThresholdReached() const {
-    return (mem_usage_ > 300000000u); // (threshold: 300 MB)
+    return (mem_usage_ > 100000000u); // (threshold: 100 MB)
   }
 
   void AddMemUsageApproximation(size_t usage) {