[6.2] Fix diagnostics for missing or invalid @_lifetime annotations on inout params

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• Fix LifetimeDependence diagnostic formatting
  Remove incorrectly nested single quotes from the suggested fix.

  (cherry picked from commit 465d6a8)

• Lifetime diagnostics: clarify @_lifetime usage for inout parameters
  This comes up often when passing a MutableSpan as an 'inout' argument. The
  vague diagnostic was causing developers to attempt incorrect @_lifetime
  annotations. Be clear about why the annotation is needed and which annotation
  should be used.

  (cherry picked from commit df0b81c)

• Fix misleading Lifetime diagnostics for inout parameters
  Correctly diagnose this as:
  "invalid use of inout dependence on the same inout parameter

  @_lifetime(a: &a)
  func f_inout_useless(a: inout MutableRawSpan) {}
  

  Correctly diagnose this as:
  "lifetime-dependent parameter must be 'inout'":

  @_lifetime(a: borrow a)
  func f_inout_useless(a: borrowing MutableRawSpan) {}
  

  (cherry picked from commit 05fa82b)

• Fix a compiler crash with '@'_lifetime(inout x), add diagnostic
  This is a common mistake made more common be suggestions of existing diagnostic
  that tell users not to use a 'copy' dependency.

  Report a diagnostic error rather than crashing the compiler. Fix the diagnostic
  output to make sense relative to the source location.

  Fixes rdar://154136015 ([nonescapable] compiler assertion with @_lifetime(x: inout x))

  (cherry picked from commit 080b682)

• Diagnostic note for invalid @_lifetime annotations on inout params
  Users commonly try to write a lifetime dependency on an 'inout' parameters as:

  @_lifetime(a: &a)
  func f_inout_useless(a: inout MutableRawSpan) {}
  

  This is useless. Guide them toward what they really wanted:

  @_lifetime(a: copy a)
  

  Fixes rdar://151618856 (@Lifetime(..) gives inconsistent error messages)

  (cherry picked from commit 87f2510)

--- CCC ---

Explanation: Fix diagnostics for missing or invalid @_lifetime annotations on inout params

Scope: This primarily affects adopters of the supported experimental Lifetimes feature but also improves diagnostic for regular non-experimental uses of MutableSpan.

Radar/SR Issue:
rdar://151618856 (@Lifetime(...) gives inconsistent error messages)
rdar://154136015 ([nonescapable] compiler assertion with @_lifetime(x: inout x))

main PR: #82505

Risk: Low. This eliminates a compiler crash and improves the quality of the diagnostic messages.

Testing: Added source-level unit tests.

Reviewer: Meghana Gupta

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@swift-ci test

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@swift-ci test macOS

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[2025-06-26T02:12:02.037Z] Cloning into 'llvm-project'...
[2025-06-26T02:12:02.037Z] error: inflate: data stream error (incorrect data check)
[2025-06-26T02:12:02.037Z] fatal: serious inflate inconsistency
[2025-06-26T02:12:02.037Z] fatal: fetch-pack: invalid index-pack output

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@swift-ci test macOS

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@swift-ci test macOS

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CI still fails for unknown reasons after four tries.

[2025-06-26T17:47:18.508Z]  > git checkout -f 9c7c3870d6154699a6616fb807850ad00564bf07 # timeout=30
[2025-06-26T17:47:22.706Z] Commit message: "Merge 384334eff8e98c4f43bb5f311cebbfee2f8015e2 into e180d8bb389aeace23be2e33bf9eb9eb5ea33a4a"
[2025-06-26T17:47:22.706Z] Using 'Changelog to branch' strategy.
[2025-06-26T17:47:22.678Z] fatal: bad revision '^origin/release/6.2'
[2025-06-26T17:47:22.743Z] ERROR: Unable to retrieve changeset
[2025-06-26T17:47:22.743Z] hudson.plugins.git.GitException: Error: git whatchanged --no-abbrev -M "--format=commit %H%ntree %T%nparent %P%nauthor %aN <%aE> %ai%ncommitter %cN <%cE> %ci%n%n%w(0,4,4)%B" -n 1024 9c7c3870d6154699a6616fb807850ad00564bf07 ^origin/release/6.2 in /Users/ec2-user/jenkins/workspace/swift-PR-macos/branch-release/6.2/swift

I'll rebase and start from scratch to see if that helps.

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@swift-ci test