Auto merge of rust-lang#55303 - alexcrichton:update-libm, r=kennytm

bors · bors · commit 1cf82fd9c0e8 · 2018-10-30T20:43:36.000Z
Update compiler-builtins submodule

This commit updates our `compiler-builtins` submodule which brings in at
least a few improvements for intrinsics on wasm32
diff --git a/src/libcompiler_builtins b/src/libcompiler_builtins
@@ -1 +1 @@
-Subproject commit 0703bfa72524e01e414477657ca9b64794c5c1c3
+Subproject commit 939cbca6e9d829265d6cf006d3532142a4061cd3
