ARM: Remove support for ABI prior to EABI

src/arm/constants-arm.h

Index: src/arm/constants-arm.h
diff --git a/src/arm/constants-arm.h b/src/arm/constants-arm.h
index a1823a1e667a7443d84ee0294c57a45384e86cc4..823c6ff7e1317795b10516a0d2350b156e06fd17 100644
--- a/src/arm/constants-arm.h
+++ b/src/arm/constants-arm.h
@@ -28,12 +28,9 @@
 #ifndef V8_ARM_CONSTANTS_ARM_H_
 #define V8_ARM_CONSTANTS_ARM_H_
 
-// The simulator emulates the EABI so we define the USE_ARM_EABI macro if we
-// are not running on real ARM hardware.  One reason for this is that the
-// old ABI uses fp registers in the calling convention and the simulator does
-// not simulate fp registers or coroutine instructions.
-#if defined(__ARM_EABI__) || !defined(__arm__)
-# define USE_ARM_EABI 1
+// ARM EABI is required.
+#if defined(__arm__) && !defined(__ARM_EABI__)
+#error ARM EABI support is required.
 #endif
 
 // This means that interwork-compatible jump instructions are generated.  We