[BOLT] Ensure remember and restore CFIs are in the same list

bolt/include/bolt/Core/BinaryFunction.h

@@ -1663,7 +1663,8 @@ class BinaryFunction {
       Offset = I->first;
     }
     assert(I->first == Offset && "CFI pointing to unknown instruction");
-    if (I == Instructions.begin()) {
+    if (I == Instructions.begin() &&
+        Inst.getOperation() != MCCFIInstruction::OpRememberState) {
       CIEFrameInstructions.emplace_back(std::forward<MCCFIInstruction>(Inst));
       return;
     }

bolt/test/AArch64/cfi-state-list.test

@@ -0,0 +1,69 @@
+// This test checks that BOLT does not split remember and restore CFI states
+// into different lists, which would cause an assertion failure.
+
+# RUN: llvm-mc -filetype=obj -triple aarch64-unknown-unknown %s -o %t.o
+# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt 2>&1 | FileCheck %s
+
+# CHECK: BOLT-INFO: Target architecture: aarch64
+# CHECK: BOLT-INFO: enabling relocation mode
+# CHECK-NOT: llvm-bolt:
+# CHECK: BOLT-INFO: Starting stub-insertion pass
+
+.text
+.global main
+.type main, %function
+
+main:
+.cfi_startproc
+.cfi_def_cfa_offset 16
+.cfi_offset x30, -8
+.cfi_remember_state
+mov	x9, #0x3ff0000000000000
+mov	x8, x0
+stp	x30, x9, [sp, #-0x10]!
+add	x3, sp, #0x8
+mov	x0, x1
+mov	x1, x2
+mov	x2, x8
+bl main
+fcmp	d0, #0.0
+b.ne main+0x34
+
+mov	w0, wzr
+ldr	x30, [sp], #0x10
+.cfi_def_cfa_offset 0
+.cfi_restore x30
+
+ret
+.cfi_restore_state
+.cfi_remember_state
+
+fmov	x8, d0
+mov	x9, #0x7ff0000000000000
+and	x8, x8, #0x7fffffffffffffff
+cmp	x8, x9
+b.lt main+0x5c
+fcmp	d0, #0.0
+mov	w8, #-0x1
+csinc	w0, w8, wzr, le
+ldr	x30, [sp], #0x10
+.cfi_def_cfa_offset 0
+.cfi_restore x30
+
+ret
+nop
+.cfi_restore_state
+
+ldr	d2, [sp, #0x8]
+mov	x8, #0x3cb0000000000000
+fabs	d1, d0
+fcmp	d0, #0.0
+fmov	d3, x8
+mov	w8, #-0x1
+csinc	w0, w8, wzr, le
+fmul	d2, d2, d3
+fcmp	d1, d2
+b.ls main+0x28
+b main+0x2c
+.cfi_endproc