[arm64] Remove remaining instances of csp

Remove final csp instances, missed in the earlier patch due to being outside
the arm64 tree.

Bug: v8:6644
Change-Id: I2b5a2716568949740991c368b64c0a06105e4ff2
Reviewed-on: https://chromium-review.googlesource.com/874310Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Martyn Capewell <martyn.capewell@arm.com>
Cr-Commit-Position: refs/heads/master@{#50698}

src/bailout-reason.h

@@ -55,8 +55,6 @@ namespace internal {
     "Should not directly enter OSR-compiled function")                         \
   V(kStackAccessBelowStackPointer, "Stack access below stack pointer")         \
   V(kStackFrameTypesMustMatch, "Stack frame types must match")                 \
-  V(kTheCurrentStackPointerIsBelowCsp,                                         \
-    "The current stack pointer is below csp")                                  \
   V(kTheStackWasCorruptedByMacroAssemblerCall,                                 \
     "The stack was corrupted by MacroAssembler::Call()")                       \
   V(kUnalignedCellInWriteBarrier, "Unaligned cell in write barrier")           \

src/globals.h

@@ -816,8 +816,6 @@ enum CpuFeature {
   MIPSr2,
   MIPSr6,
   MIPS_SIMD,  // MSA instructions
-  // ARM64
-  ALWAYS_ALIGN_CSP,
   // PPC
   FPR_GPR_MOV,
   LWSYNC,

test/cctest/test-utils-arm64.cc

@@ -286,7 +286,7 @@ void Clobber(MacroAssembler* masm, RegList reg_list, uint64_t const value) {
   for (unsigned i = 0; i < kNumberOfRegisters; i++) {
     if (reg_list & (1UL << i)) {
       Register xn = Register::Create(i, kXRegSizeInBits);
-      // We should never write into csp here.
+      // We should never write into sp here.
       CHECK(!xn.Is(sp));
       if (!xn.IsZero()) {
         if (!first.IsValid()) {
@@ -366,7 +366,7 @@ void RegisterDump::Dump(MacroAssembler* masm) {
   // Load the address where we will dump the state.
   __ Mov(dump_base, reinterpret_cast<uint64_t>(&dump_));
 
-  // Dump the stack pointer (csp and wcsp).
+  // Dump the stack pointer (sp and wsp).
   // The stack pointer cannot be stored directly; it needs to be moved into
   // another register first. Also, we pushed four X registers, so we need to
   // compensate here.

test/cctest/test-utils-arm64.h

@@ -52,8 +52,7 @@ class RegisterDump {
   RegisterDump() : completed_(false) {}
 
   // The Dump method generates code to store a snapshot of the register values.
-  // It needs to be able to use the stack temporarily, and requires that the
-  // current stack pointer is csp, and is properly aligned.
+  // It needs to be able to use the stack temporarily.
   //
   // The dumping code is generated though the given MacroAssembler. No registers
   // are corrupted in the process, but the stack is used briefly. The flags will