winch: implement atomic load operation for x64

[MarinPostma]

this PR enable the thread feature for x64 in Winch, and implements atomic loads. This includes:

• i32.atomic.load8_u
• i32.atomic.load16_u
• i32.atomic.load
• i64.atomic.load8_u
• i64.atomic.load16_u
• i64.atomic.load32_u
• i64.atomic.load

#9734

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