Extend unit test to contain a non-main source file (currently triggers failure)

Author: abertelrud

Fixtures/Miscellaneous/ExeTest/Sources/Exe/Other.swift

@@ -0,0 +1,3 @@
+public func GetOtherString() -> String {
+    return "Other"
+}

Fixtures/Miscellaneous/ExeTest/Tests/ExeTests/ExeTests.swift

@@ -6,6 +6,7 @@ final class ExeTestTests: XCTestCase {
     func testExample() throws {
         // This is an example of a test case that tries to imports an executable target.
         XCTAssertEqual(Exe.GetGreeting(), "Hello")
+        XCTAssertEqual(Exe.GetOtherString(), "Hello")
     }
 
     static var allTests = [

Tests/FunctionalTests/MiscellaneousTests.swift

@@ -523,7 +523,7 @@ class MiscellaneousTestCase: XCTestCase {
                 XCTAssertMatch(stdout, .contains("Eliding symbols from Exe_main.swift.o"))
                 XCTAssertMatch(stdout, .contains("Linking ExeTestPackageTests"))
             } catch {
-                XCTFail()
+                XCTFail("\(error)")
             }
         }
     }