Load immediates via the constant pool on armv5te and armv6.

runtime/vm/intermediate_language_arm.cc

Index: runtime/vm/intermediate_language_arm.cc
diff --git a/runtime/vm/intermediate_language_arm.cc b/runtime/vm/intermediate_language_arm.cc
index 05e9a8c9c52f79b972ebde7537f0a012aafa9be5..cc8c0e9b1bc123e5571031d882bae214e6580877 100644
--- a/runtime/vm/intermediate_language_arm.cc
+++ b/runtime/vm/intermediate_language_arm.cc
@@ -104,8 +104,11 @@ void ReturnInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ bkpt(0);
   __ Bind(&stack_ok);
 #endif
-  __ LeaveDartFrame();
+  __ LeaveDartFrame();  // Disallows constant pool use.
   __ Ret();
+  // This ReturnInstr may be emitted out of order by the optimizer. The next
+  // block may be a target expecting a properly set constant pool pointer.
+  __ set_constant_pool_allowed(true);
 }