Merge from rustc

diff --cc src/tools/miri/README.md
Simple merge

diff --cc src/tools/miri/src/eval.rs
Simple merge

diff --cc src/tools/miri/src/shims/env.rs
Simple merge

diff --cc src/tools/miri/src/shims/foreign_items.rs
Simple merge

diff --cc src/tools/miri/src/shims/unix/foreign_items.rs
Simple merge

diff --cc src/tools/miri/src/shims/unix/fs.rs
Simple merge

diff --cc src/tools/miri/src/shims/unix/linux/foreign_items.rs
index be541deae4041bdaf07b63197091cff7fbc70bbf,acf47fe924803a26523b620e8a3dda2b13d30b63..82cb21c124a2670be7a4e986555b0aa134cab0e9
--- 1/src/tools/miri/src/shims/unix/linux/foreign_items.rs
--- 2/src/tools/miri/src/shims/unix/linux/foreign_items.rs
+++ b/src/tools/miri/src/shims/unix/linux/foreign_items.rs
@@@ -178,10 -147,10 +178,10 @@@ pub trait EvalContextExt<'mir, 'tcx: 'm
                  let [pid, cpusetsize, mask] =
                      this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
                  this.read_scalar(pid)?.to_i32()?;
-                 this.read_scalar(cpusetsize)?.to_machine_usize(this)?;
+                 this.read_machine_usize(cpusetsize)?;
                  this.deref_operand(mask)?;
                  // FIXME: we just return an error; `num_cpus` then falls back to `sysconf`.
 -                let einval = this.eval_libc("EINVAL")?;
 +                let einval = this.eval_libc("EINVAL");
                  this.set_last_error(einval)?;
                  this.write_scalar(Scalar::from_i32(-1), dest)?;
              }

diff --cc src/tools/miri/src/shims/unix/macos/foreign_items.rs
index d616126cb2ab7f6c9d14f5d0ffda114a0b903c0e,2554fc77984544ee5c93b9d29d247c67bb4912a6..a55b0ee523b0880b9c5a67ee9a4fa2bfba625aac
--- 1/src/tools/miri/src/shims/unix/macos/foreign_items.rs
--- 2/src/tools/miri/src/shims/unix/macos/foreign_items.rs
+++ b/src/tools/miri/src/shims/unix/macos/foreign_items.rs
@@@ -161,14 -161,14 +161,14 @@@ pub trait EvalContextExt<'mir, 'tcx: 'm
              // Querying system information
              "pthread_get_stackaddr_np" => {
                  let [thread] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
-                 this.read_scalar(thread)?.to_machine_usize(this)?;
+                 this.read_machine_usize(thread)?;
 -                let stack_addr = Scalar::from_uint(STACK_ADDR, this.pointer_size());
 +                let stack_addr = Scalar::from_uint(this.machine.stack_addr, this.pointer_size());
                  this.write_scalar(stack_addr, dest)?;
              }
              "pthread_get_stacksize_np" => {
                  let [thread] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
-                 this.read_scalar(thread)?.to_machine_usize(this)?;
+                 this.read_machine_usize(thread)?;
 -                let stack_size = Scalar::from_uint(STACK_SIZE, this.pointer_size());
 +                let stack_size = Scalar::from_uint(this.machine.stack_size, this.pointer_size());
                  this.write_scalar(stack_size, dest)?;
              }
  

diff --cc src/tools/miri/src/shims/unix/thread.rs
Simple merge

diff --cc src/tools/miri/src/shims/windows/foreign_items.rs
index 81af325968866148545a6d4a91c4ab2e22116846,656f1a4ae72237cb5cb3fe9a70922ddbfadc21a9..1da8f7c0e3e433ff660ccd1172f6844d307b2bca
--- 1/src/tools/miri/src/shims/windows/foreign_items.rs
--- 2/src/tools/miri/src/shims/windows/foreign_items.rs
+++ b/src/tools/miri/src/shims/windows/foreign_items.rs
@@@ -73,11 -73,10 +73,11 @@@ pub trait EvalContextExt<'mir, 'tcx: 'm
              "HeapAlloc" => {
                  let [handle, flags, size] =
                      this.check_shim(abi, Abi::System { unwind: false }, link_name, args)?;
-                 this.read_scalar(handle)?.to_machine_isize(this)?;
+                 this.read_machine_isize(handle)?;
                  let flags = this.read_scalar(flags)?.to_u32()?;
-                 let size = this.read_scalar(size)?.to_machine_usize(this)?;
+                 let size = this.read_machine_usize(size)?;
 -                let zero_init = (flags & 0x00000008) != 0; // HEAP_ZERO_MEMORY
 +                let heap_zero_memory = 0x00000008; // HEAP_ZERO_MEMORY
 +                let zero_init = (flags & heap_zero_memory) == heap_zero_memory;
                  let res = this.malloc(size, zero_init, MiriMemoryKind::WinHeap)?;
                  this.write_pointer(res, dest)?;
              }

diff --cc src/tools/miri/src/shims/windows/sync.rs
Simple merge

diff --cc src/tools/miri/src/shims/windows/thread.rs
Simple merge