[ARM] Handle fixup_arm_pcrel_9 correctly on big-endian targets

[miyuki]

Summary

The getFixupKindContainerSizeBytes function returns the size of the
instruction containing a given fixup. Currently fixup_arm_pcrel_9 is
not handled in this function, this causes an assertion failure in
the debug build and incorrect codegen in the release build.

This patch fixes the problem.

[ostannard]

LGTM

llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp

static unsigned getFixupKindContainerSizeBytes(unsigned Kind) {
   case ARM::fixup_arm_thumb_br:
   case ARM::fixup_arm_thumb_cb:
     // Instruction size is 2 bytes.
     return 2;
 
   case ARM::fixup_arm_pcrel_10_unscaled:
   case ARM::fixup_arm_ldst_pcrel_12:
   case ARM::fixup_arm_pcrel_10:
+  case ARM::fixup_arm_pcrel_9:
   case ARM::fixup_arm_adr_pcrel_12:
   case ARM::fixup_arm_uncondbl:
   case ARM::fixup_arm_condbl:
   case ARM::fixup_arm_blx:
   case ARM::fixup_arm_condbranch:
   case ARM::fixup_arm_uncondbranch:
   case ARM::fixup_t2_ldst_pcrel_12:
   case ARM::fixup_t2_condbranch:

llvm/trunk/test/MC/ARM/fixup-pcrel9.s

+// RUN: llvm-mc -triple=armebv8.2a-eabi -filetype=obj < %s | llvm-objdump -s - | FileCheck %s --check-prefix=CHECK-BE
+// RUN: llvm-mc -triple=armv8.2a-eabi -filetype=obj < %s | llvm-objdump -s - | FileCheck %s --check-prefix=CHECK-LE
+
+  .text
+  .fpu  crypto-neon-fp-armv8
+        .arch_extension fp16
+
+.section s_pcrel_9,"ax",%progbits
+// CHECK-BE-LABEL: Contents of section s_pcrel_9
+// CHECK-LE-LABEL: Contents of section s_pcrel_9
+// CHECK-BE: 0000 ed9f0902
+// CHECK-LE: 0000 02099fed
+  vldr.16 s0, .LCPI0_0
+        nop
+        bx lr
+.LCPI0_0:
+  .short  28012
+