Fix unsafe expressions in NoAssignmentInExpressions

fixes #977

Author: kkebo

Sources/SwiftFormat/Rules/NoAssignmentInExpressions.swift

@@ -121,7 +121,7 @@ public final class NoAssignmentInExpressions: SyntaxFormatRule {
   private func isStandaloneAssignmentStatement(_ node: InfixOperatorExprSyntax) -> Bool {
     var node = Syntax(node)
     while let parent = node.parent,
-      parent.is(TryExprSyntax.self) || parent.is(AwaitExprSyntax.self)
+      parent.is(TryExprSyntax.self) || parent.is(AwaitExprSyntax.self) || parent.is(UnsafeExprSyntax.self)
     {
       node = parent
     }

Tests/SwiftFormatTests/Rules/NoAssignmentInExpressionsTests.swift

@@ -187,19 +187,21 @@ final class NoAssignmentInExpressionsTests: LintOrFormatRuleTestCase {
     )
   }
 
-  func testTryAndAwaitAssignmentExpressionsAreUnchanged() {
+  func testTryAndAwaitAndUnsafeAssignmentExpressionsAreUnchanged() {
     assertFormatting(
       NoAssignmentInExpressions.self,
       input: """
         func foo() {
           try a.b = c
           await a.b = c
+          unsafe a.b = c
         }
         """,
       expected: """
         func foo() {
           try a.b = c
           await a.b = c
+          unsafe a.b = c
         }
         """,
       findings: []