SI-9127 Xlint doesn't think spaces are significant

For purposes of warning about missing interpolators,
such as `"$greeting"` when the intended code was `s"$greeting"`,
spaces are no longer significant.

The heuristic was previously intended to allow compileresque
strings, where the dollar sign is a common prefix.

Currently, the Xlint warning can be selectively disabled.

1 files changed, 4 insertions, 1 deletions

diff --git a/test/files/neg/t7848-interp-warn.check b/test/files/neg/t7848-interp-warn.check
index 4cf9d55ffd..637fc8941a 100644
--- a/test/files/neg/t7848-interp-warn.check
+++ b/test/files/neg/t7848-interp-warn.check
@@ -4,9 +4,12 @@ t7848-interp-warn.scala:8: warning: possible missing interpolator: detected inte
 t7848-interp-warn.scala:12: warning: possible missing interpolator: detected an interpolated expression
     "A doubly important ${foo * 2} message!"
     ^
+t7848-interp-warn.scala:15: warning: possible missing interpolator: detected interpolated identifier `$bar`
+  def i = s"Try using '${ "$bar" }' instead."  // was: no warn on space test
+                          ^
 t7848-interp-warn.scala:16: warning: possible missing interpolator: detected interpolated identifier `$bar`
   def j = s"Try using '${ "something like $bar" }' instead."  // warn
                           ^
 error: No warnings can be incurred under -Xfatal-warnings.
-three warnings found
+four warnings found
 one error found