[APINotes] Prefer diff -u over diff -b

Lit's internal shell does not support -b (properly). This patch rewrites
the tests to conform to their existing semantics (using
--implicit-check-not) using diff -u. This allows for enabling lit's
internal shell by default on all platforms.

Fixes #106249.

Reviewers: compnerd, ilovepi, petrhosek, DougGregor

Reviewed By: ilovepi, compnerd

Pull Request: #157588

Author: boomanaiden154

clang/test/APINotes/yaml-roundtrip-2.test

@@ -1,11 +1,9 @@
 RUN: apinotes-test %S/Inputs/Frameworks/SimpleKit.framework/Headers/SimpleKit.apinotes > %t.result
-RUN: not diff -b -e %t.result %S/Inputs/Frameworks/SimpleKit.framework/Headers/SimpleKit.apinotes | FileCheck %s
-
-The `-e` option of `diff` is not implemented in the builtin diff, assume
-that we have a POSIX compatible diff when we have a shell.
-REQUIRES: shell
+RUN: not diff -u %S/Inputs/Frameworks/SimpleKit.framework/Headers/SimpleKit.apinotes %t.result | \
+RUN:   tail -n +4 | \
+RUN:   FileCheck %s --implicit-check-not="{{^\+}}" --implicit-check-not="{{^\-}}"
 
 We expect only the document markers to be emitted
 
-CHECK: 52d
-CHECK: 1d
+CHECK: +---
+CHECK: +...

clang/test/APINotes/yaml-roundtrip.test

@@ -1,30 +1,18 @@
 RUN: apinotes-test %S/Inputs/Frameworks/Simple.framework/Headers/Simple.apinotes > %t.result
-RUN: not diff -b %S/Inputs/Frameworks/Simple.framework/Headers/Simple.apinotes %t.result | FileCheck %s
-
-Avoid Windows as the diff output differs due to line-endings and different diff
-implementations.
-UNSUPPORTED: system-windows
+RUN: not diff -u %S/Inputs/Frameworks/Simple.framework/Headers/Simple.apinotes %t.result | \
+RUN:   tail -n +5 | head -n -1 | \
+RUN:   FileCheck %s --implicit-check-not="{{^\+}}" --implicit-check-not="{{^\-}}"
 
 We expect only the nullability to be different as it is canonicalized during the
 roudtrip.
 
-CHECK:      7c8
-CHECK-NEXT: <         Nullability:     N
-CHECK-NEXT: ---
-CHECK-NEXT: >         Nullability:     Nonnull
-CHECK-NEXT: 13c14
-CHECK-NEXT: <         Nullability:     O
-CHECK-NEXT: ---
-CHECK-NEXT: >         Nullability:     Optional
-CHECK-NEXT: 19c20
-CHECK-NEXT: <         Nullability:     U
-CHECK-NEXT: ---
-CHECK-NEXT: >         Nullability:     Unspecified
-CHECK-NEXT: 25c26
-CHECK-NEXT: <         Nullability:     S
-CHECK-NEXT: ---
-CHECK-NEXT: >         Nullability:     Unspecified
-CHECK-NEXT: 28c29
-CHECK-NEXT: <         Nullability:     Scalar
-CHECK-NEXT: ---
-CHECK-NEXT: >         Nullability:     Unspecified
+CHECK:      -        Nullability:     N
+CHECK-NEXT: +        Nullability:     Nonnull
+CHECK:      -        Nullability:     O
+CHECK-NEXT: +        Nullability:     Optional
+CHECK:      -        Nullability:     U
+CHECK-NEXT: +        Nullability:     Unspecified
+CHECK:      -        Nullability:     S
+CHECK-NEXT: +        Nullability:     Unspecified
+CHECK:      -        Nullability:     Scalar
+CHECK-NEXT: +        Nullability:     Unspecified