MIPS: Fix debug mode failures introduced by r15561.

src/mips/code-stubs-mips.cc

Index: src/mips/code-stubs-mips.cc
diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index 770d4e7c246d8714509f5da615caed9903a913e2..5ff453331729592e4bb4ec0c43952a6c561896e1 100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -6960,6 +6960,9 @@ void StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime(
     Isolate* isolate) {
   StoreBufferOverflowStub stub1(kDontSaveFPRegs);
   stub1.GetCode(isolate)->set_is_pregenerated(true);
+  // Hydrogen code stubs need stub2 at snapshot time.
+  StoreBufferOverflowStub stub2(kSaveFPRegs);
+  stub2.GetCode(isolate)->set_is_pregenerated(true);
 }