[Chapel Merge] Disable an assertion to turn an assertion error fo

Branch: refs/heads/master
Revision: 2e5f950
Author: bradcray
Log Message:

Merge pull request #16863 from bradcray/disable-loop-expr-assertion

Disable an assertion to turn an assertion error for incorrect user programs into a user-facing error

[reviewed by @mppf]

This addresses user issue #16860 in which an early assertion
in the compiler generated an internal error for unsupported
patterns in user code when the lack of the assertion results
in a user-facing error message later in compilation. Specifically,
I removed the assertion and let the error case through.

Tested linux64 for everything and the new test with --verify,
ASAN, and valgrind.

Resolves #16860.

Modified Files:
A test/classes/delete-free/borrowed/borrowed-array.chpl
A test/classes/delete-free/borrowed/borrowed-array.good
M compiler/AST/LoopExpr.cpp

Compare: https://github.com/chapel-lang/chapel/compare/cd0ff1901248...2e5f9504121e