Revert runtime work queue patch, it breaks some tests that need investigation (#143713)

Revert "[flang][runtime] Another try to fix build failure"

This reverts commit 13869cac2b5051e453aa96ad71220d9d33404620.

Revert "[flang][runtime] Fix build bot flang-runtime-cuda-gcc errors
(#143650)"

This reverts commit d75e28477a.

Revert "[flang][runtime] Replace recursion with iterative work queue
(#137727)"

This reverts commit 163c67ad3d.

flang/docs/Extensions.md

@@ -858,16 +858,6 @@ print *, [(j,j=1,10)]
   warning since such values may have become defined by the time the nested
   expression's value is required.
 
-* Intrinsic assignment of arrays is defined elementally, and intrinsic
-  assignment of derived type components is defined componentwise.
-  However, when intrinsic assignment takes place for an array of derived
-  type, the order of the loop nesting is not defined.
-  Some compilers will loop over the elements, assigning all of the components
-  of each element before proceeding to the next element.
-  This compiler loops over all of the components, and assigns all of
-  the elements for each component before proceeding to the next component.
-  A program using defined assignment might be able to detect the difference.
-
 ## De Facto Standard Features
 
 * `EXTENDS_TYPE_OF()` returns `.TRUE.` if both of its arguments have the