[Caching] remove implicit cast from CachedWord to Word (1.7%)

[adamsitnik]

load	before	after
CPU Usage (%)	22	22
Cores usage (%)	605	615
Working Set (MB)	48	48
Build Time (ms)	3,733	3,973
Start Time (ms)	0	0
Published Size (KB)	76,401	76,401
First Request (ms)	67	66
Requests/sec	268,293	272,573
Requests	4,051,004	4,115,679
Mean latency (ms)	1.11	1.11
Max latency (ms)	41.51	42.72
Bad responses	0	0
Socket errors	0	0
Read throughput (MB/s)	844.32	857.79
Latency 50th (ms)	0.93	0.91
Latency 75th (ms)	1.03	1.01
Latency 90th (ms)	1.15	1.14
Latency 99th (ms)	8.74	9.01

[adamsitnik]

@sebastienros ping

[sebastienros]

I was giving @benaadams some time to comment too.

[benaadams]

I was giving @benaadams some time to comment too.

PR to TE? Not long left for Round 20

[adamsitnik]

PR to TE? Not long left for Round 20

It was just 1.7% and all my MemoryCache improvements will be part of 6.0, so I think that we can skip this round for this particular benchmark.