Fix table(), set(), vector() constructors in table initializer lists.

Also adds type checking of yield values to table() constructor and
fixes the type checking of yield values in vector() constructor.

Addresses #5.

testing/btest/Baseline/language.table-init-container-ctors/output

@@ -0,0 +1,42 @@
+table of set
+{
+[13] = {
+[bar, 2] ,
+[foo, 1] 
+},
+[5] = {
+[bah, 3] ,
+[baz, 4] 
+}
+}
+
+table of vector
+{
+[13] = [1, 2],
+[5] = [3, 4]
+}
+
+table of table
+{
+[13] = {
+[bar, 2] = 2,
+[foo, 1] = 1
+},
+[5] = {
+[bah, 3] = 3,
+[baz, 4] = 4
+}
+}
+
+T
+T
+T
+T
+T
+T
+T
+T
+T
+T
+T
+T