Revert "OS-8005 bhyve memory pressure needs to target ARC better (#354)"
This reverts commit a6033573eedd94118d2b9e65f45deca0bf4b42f7.

*** 36,46 ****
   * A full copy of the text of the CDDL should have accompanied this
   * source.  A copy of the CDDL is also available via the Internet at
   * http://www.illumos.org/license/CDDL.
   *
   * Copyright 2015 Pluribus Networks Inc.
!  * Copyright 2020 Joyent, Inc.
   * Copyright 2020 Oxide Computer Company
   */
  
  #ifndef _VMMAPI_H_
  #define _VMMAPI_H_
--- 36,46 ----
   * A full copy of the text of the CDDL should have accompanied this
   * source.  A copy of the CDDL is also available via the Internet at
   * http://www.illumos.org/license/CDDL.
   *
   * Copyright 2015 Pluribus Networks Inc.
!  * Copyright 2019 Joyent, Inc.
   * Copyright 2020 Oxide Computer Company
   */
  
  #ifndef _VMMAPI_H_
  #define _VMMAPI_H_
*** 314,324 ****
  int     vm_wrlock_cycle(struct vmctx *ctx);
  int vm_get_run_state(struct vmctx *ctx, int vcpu, enum vcpu_run_state *state,
      uint8_t *sipi_vector);
  int vm_set_run_state(struct vmctx *ctx, int vcpu, enum vcpu_run_state state,
      uint8_t sipi_vector);
- int     vm_arc_resv(struct vmctx *ctx, size_t);
  #endif  /* __FreeBSD__ */
  
  #ifdef  __FreeBSD__
  /*
   * FreeBSD specific APIs
--- 314,323 ----