Move the logic to negate a flag properly if the name starts with '!' to
the general {FlagName} helper. This fixes an otherwise weird formatting.

Before:
# Contradictory flag implications from --!liftoff and --wasm-speculative-inlining for flag --wasm-dynamic-tiering.

After:
# Contradictory flag implications from --no-liftoff and --wasm-speculative-inlining for flag --wasm-dynamic-tiering.

R=tebbi@chromium.org

Change-Id: I21236b4ff338aa4d2ddd0872f85e2362ef8dc813
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3870915
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82943}