Remove --stop-at flag from several backends.

src/crankshaft/arm/lithium-codegen-arm.cc

Index: src/crankshaft/arm/lithium-codegen-arm.cc
diff --git a/src/crankshaft/arm/lithium-codegen-arm.cc b/src/crankshaft/arm/lithium-codegen-arm.cc
index 77d83ac5da5d7fe926a33c803e04429c7ab2ed39..b799a1daad014bef325156f4347c3aa7614012fd 100644
--- a/src/crankshaft/arm/lithium-codegen-arm.cc
+++ b/src/crankshaft/arm/lithium-codegen-arm.cc
@@ -103,13 +103,6 @@ bool LCodeGen::GeneratePrologue() {
   if (info()->IsOptimizing()) {
     ProfileEntryHookStub::MaybeCallEntryHook(masm_);
 
-#ifdef DEBUG
-    if (strlen(FLAG_stop_at) > 0 &&
-        info_->literal()->name()->IsUtf8EqualTo(CStrVector(FLAG_stop_at))) {
-      __ stop("stop_at");
-    }
-#endif
-
     // r1: Callee's JS function.
     // cp: Callee's context.
     // pp: Callee's constant pool pointer (if enabled)