Use "realpath" when creating test file to test tests

Now that we call "realpath" when loading files, we should get the
expected output on systems like macOS where the temporary directory is
a symlink.

Author: d-torrance

M2/Macaulay2/tests/normal/testing.m2

@@ -1,4 +1,4 @@
-testpkg = minimizeFilename(temporaryFileName() | ".m2")
+testpkg = toAbsolutePath(temporaryFileName() | ".m2")
 testpkg << ///newPackage("TestPackage")
 beginDocumentation()
 TEST "assert Equation(1 + 1, 2)"
@@ -11,7 +11,7 @@ assert Equation(toSequence locate pkgtest, (testpkg, 3, 5, 3, 32, 3, 5))
 assert Equation(toString pkgtest, concatenate(
 	"-- test source: ", toString locate pkgtest, newline,
 	"assert Equation(1 + 1, 2)"))
-assert Equation(net pkgtest, "TestInput[" | testpkg | ":3:5-3:32]")
+assert Equation(net pkgtest, "TestInput[" | realpath testpkg | ":3:5-3:32]")
 beginDocumentation()
 expectedCode = DIV{
     new FilePosition from (testpkg, 3, 5, 3, 32, 3, 5),