Add BLAKE3 Hashing/XOF to stdlib (#2667)

* blake3: initial unit test passing!

* typo

* add key derivation macros; vanilla unit tests; working to test 18 atm

* mark it here - all tests passing o_o

* finish first-round unit tests - will add more if necessary

* add crypto shootout bench entertainment

* tests: add XOF unit w/ seek; assert NO finalization

* add another to finalizations unit test

* add all BLAKE3 scaffolding for later SIMD optimizations

* irksome

* tabs

* tabs2

* extra documentation / contracts

* extra detail

* try to make things a bit more arch-neutral

* release notes

* Formatting

---------

Co-authored-by: Christoffer Lerno <christoffer@aegik.com>

src/compiler/sema_expr.c

@@ -6915,7 +6915,7 @@ static bool sema_expr_analyse_slice_assign(SemaContext *context, Expr *expr, Typ
 				case TYPE_SLICE:
 					break;
 				default:
-					RETURN_SEMA_ERROR(right, "You trying to assign this expression to each element in the slice, but the expression can't be cast to a value of type %s. Maybe you wanted to do a slice copy and forgot to add [..] at the end? Rather than 'a[..] = { ... }', try 'a[..] = { ... }[..]'.",
+					RETURN_SEMA_ERROR(right, "You are trying to assign this expression to each element in the slice, but the expression can't be cast to a value of type %s. Maybe you wanted to do a slice copy and forgot to add [..] at the end? Rather than 'a[..] = { ... }', try 'a[..] = { ... }[..]'.",
 						type_quoted_error_string(base));
 			}
 		}