ART: Use kBadFprBase on mips64 and arm64.

Fix incorrect usage of kBadGprBase to avoid misleading and
ambiguous data in crash investigations.

Bug: 21266656

(cherry picked from commit 5b09ea0af468d9232cf725ac7f7e73c145892c5c)

Change-Id: Ia4fc60a5d61471c7a6c8fd0545a897ace43d90be
diff --git a/runtime/arch/arm64/context_arm64.cc b/runtime/arch/arm64/context_arm64.cc
index 9c7bb55..cb5b9e1 100644
--- a/runtime/arch/arm64/context_arm64.cc
+++ b/runtime/arch/arm64/context_arm64.cc
@@ -133,7 +133,7 @@
     gprs[i] = gprs_[i] != nullptr ? *gprs_[i] : Arm64Context::kBadGprBase + i;
   }
   for (size_t i = 0; i < kNumberOfDRegisters; ++i) {
-    fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : Arm64Context::kBadGprBase + i;
+    fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : Arm64Context::kBadFprBase + i;
   }
   DCHECK_EQ(reinterpret_cast<uintptr_t>(Thread::Current()), gprs[TR]);
   art_quick_do_long_jump(gprs, fprs);
diff --git a/runtime/arch/mips/context_mips.cc b/runtime/arch/mips/context_mips.cc
index f0c893a..24892e9 100644
--- a/runtime/arch/mips/context_mips.cc
+++ b/runtime/arch/mips/context_mips.cc
@@ -87,7 +87,7 @@
     gprs[i] = gprs_[i] != nullptr ? *gprs_[i] : MipsContext::kBadGprBase + i;
   }
   for (size_t i = 0; i < kNumberOfFRegisters; ++i) {
-    fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : MipsContext::kBadGprBase + i;
+    fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : MipsContext::kBadFprBase + i;
   }
   art_quick_do_long_jump(gprs, fprs);
 }