Fix two register leaks in the trusted->untrusted context switch

tests/thread_suspension/suspend_test_guest.c

 /*
  * Copyright (c) 2012 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "native_client/tests/thread_suspension/suspend_test.h"
 
 #include <assert.h>
 #include <setjmp.h>
@@ skipping 91 matching lines @@
 #else
 # error Unsupported architecture
 #endif
   assert(!"Should not reach here");
 }
 
 static void ContinueAfterSyscall(void) {
   longjmp(return_jmp_buf, 1);
 }
 
-static void UnsetNonCalleeSavedRegisters(struct NaClSignalContext *regs) {
-#if defined(__i386__)
-  regs->eax = 0;
-  regs->ecx = 0;
-  regs->edx = 0;
-#elif defined(__x86_64__)
-  regs->rax = 0;
-  regs->rcx = 0;
-  regs->rdx = 0;
-  regs->rsi = 0;
-  regs->rdi = 0;
-  regs->r8 = 0;
-  regs->r9 = 0;
-  regs->r10 = 0;
-  regs->r11 = 0;
-#elif defined(__arm__)
-  regs->r0 = 0;
-  regs->r1 = 0;
-  regs->r2 = 0;
-  regs->r3 = 0;
-  regs->r12 = 0;
-  regs->lr = 0;
-#else
-# error Unsupported architecture
-#endif
-}
-
 /* Set registers to known values and enter a NaCl syscall. */
 static void SyscallRegisterSetterThread(struct SuspendTestShm *test_shm) {
   struct NaClSignalContext call_regs;
   char stack[0x10000];
 
   RegsFillTestValues(&call_regs);
   call_regs.stack_ptr = (uintptr_t) stack + sizeof(stack);
   call_regs.prog_ctr = (uintptr_t) ContinueAfterSyscall;
   RegsApplySandboxConstraints(&call_regs);
 
   /*
    * call_regs are the registers we set on entry to the syscall.
    * expected_regs are the registers that should be reported by
    * NaClAppThreadGetSuspendedRegisters().  Since not all registers
    * are saved when entering a syscall, expected_regs will be the same
    * as call_regs but with various registers zeroed out.
    */
   test_shm->expected_regs = call_regs;
-  UnsetNonCalleeSavedRegisters(&test_shm->expected_regs);
+  RegsUnsetNonCalleeSavedRegisters(&test_shm->expected_regs);
 
   uintptr_t syscall_addr = (uintptr_t) NACL_SYSCALL(test_syscall_1);
   if (!setjmp(return_jmp_buf)) {
 #if defined(__i386__)
     test_shm->expected_regs.stack_ptr -= 4;  /* Account for argument */
     call_regs.eax = syscall_addr;
     call_regs.ecx = (uintptr_t) test_shm;  /* Scratch register */
     ASM_WITH_REGS(
         &call_regs,
         "push %%ecx\n"  /* Push syscall argument */
@@ skipping 42 matching lines @@
   } else if (strcmp(test_type, "RegisterSetterThread") == 0) {
     RegisterSetterThread(test_shm);
   } else if (strcmp(test_type, "SyscallRegisterSetterThread") == 0) {
     SyscallRegisterSetterThread(test_shm);
   } else {
     fprintf(stderr, "Unknown test type: %s\n", test_type);
     return 1;
   }
   return 0;
 }