[WebAssembly] Set the scheduling preference.

llvm-svn: 241637
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index 4eec02e..4184eb6 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -38,6 +38,8 @@
   // WebAssembly does not produce floating-point exceptions on normal floating
   // point operations.
   setHasFloatingPointExceptions(false);
+  // We don't know the microarchitecture here, so just reduce register pressure.
+  setSchedulingPreference(Sched::RegPressure);
 }
 
 //===----------------------------------------------------------------------===//