[spec] Array literal can implicitly convert to an expected type

[ntrel]

Fix Issue 24177 - Array literal can implicitly convert to an expected type.

Use this feature to avoid casting elements manually in example.
Also extend array literal to static array example.

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	16357	normal	cast(T[])[x] casts x to T instead of [x] to T[]
✓	24177	enhancement	Array literal can implicitly convert to an expected type