ART: Do not use std::<container>::at().

These functions are specified as throwing std::out_of_range
and we do not use exceptions.

Test: m
Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Change-Id: I67c365ed6d779c101a18b9f386c751c48ca76e16
diff --git a/compiler/utils/arm/jni_macro_assembler_arm_vixl.cc b/compiler/utils/arm/jni_macro_assembler_arm_vixl.cc
index 2c428fa..c6c764e 100644
--- a/compiler/utils/arm/jni_macro_assembler_arm_vixl.cc
+++ b/compiler/utils/arm/jni_macro_assembler_arm_vixl.cc
@@ -120,11 +120,10 @@
 
   // Write out entry spills.
   int32_t offset = frame_size + kFramePointerSize;
-  for (size_t i = 0; i < entry_spills.size(); ++i) {
-    ArmManagedRegister reg = entry_spills.at(i).AsArm();
+  for (const ManagedRegisterSpill& spill : entry_spills) {
+    ArmManagedRegister reg = spill.AsArm();
     if (reg.IsNoRegister()) {
       // only increment stack offset.
-      ManagedRegisterSpill spill = entry_spills.at(i);
       offset += spill.getSize();
     } else if (reg.IsCoreRegister()) {
       asm_.StoreToOffset(kStoreWord, AsVIXLRegister(reg), sp, offset);
diff --git a/compiler/utils/arm64/jni_macro_assembler_arm64.cc b/compiler/utils/arm64/jni_macro_assembler_arm64.cc
index a5aa1c1..d6ce033 100644
--- a/compiler/utils/arm64/jni_macro_assembler_arm64.cc
+++ b/compiler/utils/arm64/jni_macro_assembler_arm64.cc
@@ -719,11 +719,10 @@
 
   // Write out entry spills
   int32_t offset = frame_size + static_cast<size_t>(kArm64PointerSize);
-  for (size_t i = 0; i < entry_spills.size(); ++i) {
-    Arm64ManagedRegister reg = entry_spills.at(i).AsArm64();
+  for (const ManagedRegisterSpill& spill : entry_spills) {
+    Arm64ManagedRegister reg = spill.AsArm64();
     if (reg.IsNoRegister()) {
       // only increment stack offset.
-      ManagedRegisterSpill spill = entry_spills.at(i);
       offset += spill.getSize();
     } else if (reg.IsXRegister()) {
       StoreToOffset(reg.AsXRegister(), SP, offset);
diff --git a/compiler/utils/managed_register.h b/compiler/utils/managed_register.h
index 2b7b2aa..db9c36c 100644
--- a/compiler/utils/managed_register.h
+++ b/compiler/utils/managed_register.h
@@ -101,11 +101,11 @@
   ManagedRegisterSpill(const ManagedRegister& other, int32_t size)
       : ManagedRegister(other), size_(size), spill_offset_(-1) { }
 
-  int32_t getSpillOffset() {
+  int32_t getSpillOffset() const {
     return spill_offset_;
   }
 
-  int32_t getSize() {
+  int32_t getSize() const {
     return size_;
   }
 
diff --git a/compiler/utils/mips/assembler_mips.cc b/compiler/utils/mips/assembler_mips.cc
index dce5b95..c0b6f98 100644
--- a/compiler/utils/mips/assembler_mips.cc
+++ b/compiler/utils/mips/assembler_mips.cc
@@ -4801,10 +4801,9 @@
 
   // Write out entry spills.
   int32_t offset = frame_size + kFramePointerSize;
-  for (size_t i = 0; i < entry_spills.size(); ++i) {
-    MipsManagedRegister reg = entry_spills.at(i).AsMips();
+  for (const ManagedRegisterSpill& spill : entry_spills) {
+    MipsManagedRegister reg = spill.AsMips();
     if (reg.IsNoRegister()) {
-      ManagedRegisterSpill spill = entry_spills.at(i);
       offset += spill.getSize();
     } else if (reg.IsCoreRegister()) {
       StoreToOffset(kStoreWord, reg.AsCoreRegister(), SP, offset);
diff --git a/compiler/utils/mips64/assembler_mips64.cc b/compiler/utils/mips64/assembler_mips64.cc
index bb1bb82..5b1c5d9 100644
--- a/compiler/utils/mips64/assembler_mips64.cc
+++ b/compiler/utils/mips64/assembler_mips64.cc
@@ -3633,9 +3633,8 @@
 
   // Write out entry spills.
   int32_t offset = frame_size + kFramePointerSize;
-  for (size_t i = 0; i < entry_spills.size(); ++i) {
-    Mips64ManagedRegister reg = entry_spills[i].AsMips64();
-    ManagedRegisterSpill spill = entry_spills.at(i);
+  for (const ManagedRegisterSpill& spill : entry_spills) {
+    Mips64ManagedRegister reg = spill.AsMips64();
     int32_t size = spill.getSize();
     if (reg.IsNoRegister()) {
       // only increment stack offset.
diff --git a/compiler/utils/x86/jni_macro_assembler_x86.cc b/compiler/utils/x86/jni_macro_assembler_x86.cc
index 7e29c4a..dd99f03 100644
--- a/compiler/utils/x86/jni_macro_assembler_x86.cc
+++ b/compiler/utils/x86/jni_macro_assembler_x86.cc
@@ -67,8 +67,7 @@
   cfi().AdjustCFAOffset(kFramePointerSize);
   DCHECK_EQ(static_cast<size_t>(cfi().GetCurrentCFAOffset()), frame_size);
 
-  for (size_t i = 0; i < entry_spills.size(); ++i) {
-    ManagedRegisterSpill spill = entry_spills.at(i);
+  for (const ManagedRegisterSpill& spill : entry_spills) {
     if (spill.AsX86().IsCpuRegister()) {
       int offset = frame_size + spill.getSpillOffset();
       __ movl(Address(ESP, offset), spill.AsX86().AsCpuRegister());
diff --git a/compiler/utils/x86_64/jni_macro_assembler_x86_64.cc b/compiler/utils/x86_64/jni_macro_assembler_x86_64.cc
index 9486cb4..f6b2f9d 100644
--- a/compiler/utils/x86_64/jni_macro_assembler_x86_64.cc
+++ b/compiler/utils/x86_64/jni_macro_assembler_x86_64.cc
@@ -75,8 +75,7 @@
 
   __ movq(Address(CpuRegister(RSP), 0), method_reg.AsX86_64().AsCpuRegister());
 
-  for (size_t i = 0; i < entry_spills.size(); ++i) {
-    ManagedRegisterSpill spill = entry_spills.at(i);
+  for (const ManagedRegisterSpill& spill : entry_spills) {
     if (spill.AsX86_64().IsCpuRegister()) {
       if (spill.getSize() == 8) {
         __ movq(Address(CpuRegister(RSP), frame_size + spill.getSpillOffset()),