SI-8549 Honour the @SerialVersionUID annotatation

In PR #1673 / 4267444, the annotation `SerialVersionId` was
changed from a `StaticAnnotation` to `ClassFileAnnotation` in
order to avoid silently ignoring non-literal UIDs like:

    @SerialVersionUID(0 - 12345L) class C

And to flag non-constant UIDs:

    @SerialVersionUID("!!!".length)

While this indeed was fold constants, the change was incomplete.
The compiler API for reading the argument from a `ClassFileAnnoation`
is different, on must look for a `LiteralAnnotArg`, rather than a
`Literal`.

This commit:

  - amends the backend accordingly
  - removes relevant duplication between `GenASM` and `GenBCode`
  - tests that the static field is generated accordingly

This will mean that we will break deserialization of objects from
Scalal 2.11.0 that use this annotation.

1 files changed, 16 insertions, 0 deletions

diff --git a/test/files/run/t8549b.scala b/test/files/run/t8549b.scala
new file mode 100644
index 0000000000..1e1bf2c0bc
--- /dev/null
+++ b/test/files/run/t8549b.scala
@@ -0,0 +1,16 @@
+
+@SerialVersionUID(42)
+class C
+
+@SerialVersionUID(43 - 1)
+class D
+
+
+object Test extends App {
+  def checkId(cls: Class[_]) {
+    val id = cls.getDeclaredField("serialVersionUID").get(null)
+    assert(id == 42, (cls, id))  
+  }
+  checkId(classOf[C])
+  checkId(classOf[D])
+}