Use new names for Swift 6 mode

Author: glessard

Sources/System/Internals/Exports.swift

@@ -140,7 +140,7 @@ extension String {
     return
 
     #else
-    self.init(validatingUTF8: platformString)
+    self.init(validatingCString: platformString)
     #endif
   }
 

Tests/SystemTests/FilePathTests/FilePathComponentsTest.swift

@@ -107,7 +107,7 @@ final class FilePathComponentsTest: XCTestCase {
 
     func expect(
       _ s: String,
-      _ file: StaticString = #file,
+      _ file: StaticString = #filePath,
       _ line: UInt = #line
     ) {
       if path == FilePath(s) { return }

Tests/SystemTests/FilePathTests/FilePathSyntaxTest.swift

@@ -850,7 +850,7 @@ final class FilePathSyntaxTest: XCTestCase {
 
     func expect(
       _ s: String,
-      _ file: StaticString = #file,
+      _ file: StaticString = #filePath,
       _ line: UInt = #line
     ) {
       if path == FilePath(s) { return }

Tests/SystemTests/UtilTests.swift

@@ -34,7 +34,7 @@ class UtilTests: XCTestCase {
   func testCStringArray() {
     func check(
       _ array: [String],
-      file: StaticString = #file,
+      file: StaticString = #filePath,
       line: UInt = #line
     ) {
       array._withCStringArray { carray in