Make coercion behaviour more explicit

Make it explicit that not matching any of the Enum or Array coercion
options results in an error

spec/src/main/asciidoc/ELSpec.adoc

diff --git a/spec/src/main/asciidoc/ELSpec.adoc b/spec/src/main/asciidoc/ELSpec.adoc
index 38b13a8..2a7a659 100644
--- a/spec/src/main/asciidoc/ELSpec.adoc
+++ b/spec/src/main/asciidoc/ELSpec.adoc
@@ -1501,6 +1501,8 @@
 * If `A` is a `String` call `Enum.valueOf(T.getClass(), A)` and return
 the result
 
+* Otherwise, error
+
 ==== Coerce `A` to an array of Type `T`
 
 * If `A` is `null`, return `null`
@@ -1509,6 +1511,8 @@
 
 * If `A` is an array, return a copy of the array where each element has been coerced to type `T` using these rules
 
+* Otherwise, error
+
 Note: If coercion of any element in the array fails, the coercion of the array fails
 
 ==== Coerce `A` to functional interface method invocation