test: add Swift 6.1.0 to compiletime crash tests

Author: Chaitanya Kumar

.github/workflows/test.yml

@@ -14,7 +14,7 @@ jobs:
  runs-on: ubuntu-latest
  strategy:
  matrix:
- swift: ["6.0.3"]
+ swift: ["6.0.3", "6.1.0"]
  container: swift:${{ matrix.swift }}
  steps:
  - uses: actions/checkout@v4

CompiletimeCrashTests/c003-nil-coalescing-silgen-crash/expected-6.1.0-Linux.txt

@@ -0,0 +1 @@
+# OK

CompiletimeCrashTests/c011-assertion-failed-adjoint-buffer-exists/expected-6.1.0-Linux.txt

@@ -0,0 +1 @@
+# OK

CompiletimeCrashTests/c012-sil-verification-failed-method-not-in-vtable/expected-6.1.0-Linux.txt

@@ -0,0 +1 @@
+# OK

CompiletimeCrashTests/c012-sil-verification-failed-method-not-in-vtable/main.swift

@@ -6,7 +6,8 @@ import _Differentiation
 public protocol TensorView {
  associatedtype Element
 }
-public protocol DifferentiableTensorView: TensorView & Differentiable where Self == TangentVector {}
+// NB: `AdditiveArithmetic` added in response to warning in Swift 6.1
+public protocol DifferentiableTensorView: AdditiveArithmetic & TensorView & Differentiable where Self == TangentVector {}
 
 public protocol PlatformAPI {
  @differentiable(reverse)