Sort allocas, compute frame pointer in Cfg pass

src/IceTargetLoweringMIPS32.h

Index: src/IceTargetLoweringMIPS32.h
diff --git a/src/IceTargetLoweringMIPS32.h b/src/IceTargetLoweringMIPS32.h
index 5ac097608f709d62b3f52e8769bc191677b27881..3cd1687ea0ed1ae1458d946a7299702f00b398f2 100644
--- a/src/IceTargetLoweringMIPS32.h
+++ b/src/IceTargetLoweringMIPS32.h
@@ -49,6 +49,7 @@ public:
     return RegisterAliases[Reg];
   }
   bool hasFramePointer() const override { return UsesFramePointer; }
+  void setHasFramePointer() override { UsesFramePointer = true; }
   SizeT getStackReg() const override { return RegMIPS32::Reg_SP; }
   SizeT getFrameOrStackReg() const override {
     return UsesFramePointer ? RegMIPS32::Reg_FP : RegMIPS32::Reg_SP;
@@ -58,6 +59,10 @@ public:
     // are rounded up to 4 bytes.
     return (typeWidthInBytes(Ty) + 3) & ~3;
   }
+  uint32_t getStackAlignment() const override {
+    // TODO(sehr): what is the stack alignment?
+    return 1;
+  }
 
   bool shouldSplitToVariable64On32(Type Ty) const override {
     return Ty == IceType_i64;