Allow reading Package.swift with the executable bit set

786c513 added support for symlinks, but
didn't handle `executableBlob` in the added `switch`. `executableBlob`
is the returned type for a file with the executable bit set, so needs to
be handled in the same way as a regular `blob`.

Author: bnbarham

Sources/SourceControl/GitRepository.swift

@@ -1105,7 +1105,7 @@ private class GitFileSystemView: FileSystem {
         case .symlink:
             let path = try repository.readLink(hash: hash)
             return try readFileContents(AbsolutePath(validating: path))
-        case .blob:
+        case .blob, .executableBlob:
             return try self.repository.readBlob(hash: hash)
         default:
             throw InternalError("unsupported git entry type \(entry.type) at path \(path)")

Tests/SourceControlTests/GitRepositoryTests.swift

@@ -291,6 +291,7 @@ class GitRepositoryTests: XCTestCase {
             // Check read of a file.
             XCTAssertEqual(try view.readFileContents("/test-file-1.txt"), test1FileContents)
             XCTAssertEqual(try view.readFileContents("/subdir/test-file-2.txt"), test2FileContents)
+            XCTAssertEqual(try view.readFileContents("/test-file-3.sh"), test3FileContents)
         }
     }