SFENCE - Throughput and Uops

With unroll_count=500 and no inner loop

Code:
```
   0:	0f ae f8             	sfence 
```
Init:
```
VZEROALL
```
Show nanoBench command
Results:
- MPERF: 0.88
- APERF: 1.0
- UOPS: 1.0
- FpuPipeAssignment.Total0: 0.0
- FpuPipeAssignment.Total1: 0.0
- FpuPipeAssignment.Total2: 0.0
- FpuPipeAssignment.Total3: 0.0
- FpuPipeAssignment.Total4: 0.0
- FpuPipeAssignment.Total5: 0.0
- DIV_CYCLES: 0.0

With loop_count=1000 and unroll_count=10

Code:
```
   0:	0f ae f8             	sfence 
```
Init:
```
VZEROALL
```
Show nanoBench command
Results:
- MPERF: 0.86
- APERF: 1.0
- UOPS: 1.1
- FpuPipeAssignment.Total0: 0.0
- FpuPipeAssignment.Total1: 0.0
- FpuPipeAssignment.Total2: 0.0
- FpuPipeAssignment.Total3: 0.0
- FpuPipeAssignment.Total4: 0.0
- FpuPipeAssignment.Total5: 0.0
- DIV_CYCLES: 0.0

With loop_count=100 and unroll_count=100

Code:
```
   0:	0f ae f8             	sfence 
```
Init:
```
VZEROALL
```
Show nanoBench command
Results:
- MPERF: 0.86
- APERF: 1.0
- UOPS: 1.01
- FpuPipeAssignment.Total0: 0.0
- FpuPipeAssignment.Total1: 0.0
- FpuPipeAssignment.Total2: 0.0
- FpuPipeAssignment.Total3: 0.0
- FpuPipeAssignment.Total4: 0.0
- FpuPipeAssignment.Total5: 0.0
- DIV_CYCLES: 0.0