Revert "am c6c317e1: Experimental."

This reverts commit 5b6d8b3ef4f97975beed542c661d8f395593a7d1, reversing
changes made to 621b1d44932bf8be41e11f3ad34cb667b466807d.
diff --git a/src/compiler_llvm/compilation_unit.cc b/src/compiler_llvm/compilation_unit.cc
index c5952f0..0c6c58d 100644
--- a/src/compiler_llvm/compilation_unit.cc
+++ b/src/compiler_llvm/compilation_unit.cc
@@ -139,7 +139,6 @@
   target_options.NoFramePointerElim = true;
   target_options.NoFramePointerElimNonLeaf = true;
   target_options.UseSoftFloat = false;
-  target_options.EnableFastISel = true;
 
   // Create the llvm::TargetMachine
   llvm::TargetMachine* target_machine =