5.10: [Test] Restrict test to release stdlibs.

**Description**: Run OSLogMandatoryOptTest.swift only in configurations with release stdlibs.

#70068 introduced a simple but widespread change to SIL.  It required updating a number of tests.  The updates amounted to inserting numerous of `begin_borrow [var_decl]` instructions.

On 5.10--but not main--OSLogMandatoryOptTest.swift had to be updated as well: several new `begin_borrow [var_decl]` instructions had to be FileCheck'd.  These instructions all came from inlining code from the OSLogTestHelper target, a target which is built in the same configuration as the stdlib.  In fact, they all came from inlining the `_osLogTestHelper(_:assertion:)` function.

When building OSLogTestHelper for release, no optimization passes are run on the function because it is marked `@_optimize(none)`.  `SemanticARCOpts` would have deleted these borrow scopes, but it doesn't run on the function.

When building OSLogTestHelper for debug, however, `MandatoryARCOpts` (a subset of `SemanticARCOpts`) _does_ run despite the function being marked `@_optimize(none)`.  That's because it's part of the `OnonePassPipeline` which is mandatory, meaning that every pass runs on each function, regardless of it being annotated `@_optimize(none)`.

As a result the `begin_borrow [var_decl]` instructions--which FileCheck lines were added to match--are deleted before FileCheck runs.  So the new check lines fail to match the deleted instructions.  Besides the absence of these new `begin_borrow [var_decl]` instructions, there is no difference between the function in debug vs release.  In particular, removing the newly added check lines allows the test to pass in a configuration with a debug stdlib.

Rather than duplicate the test for debug configurations, just disable it in them.

----

On main, the new `begin_borrow [var_decl]` instructions were already deleted by a new mandatory `begin_borrow` simplification that exists only on main but not release/5.10, so they weren't present to be FileCheck'd in either configuration, which is why the test wasn't updated for main.

Risk: None.  Test-only change.

**Scope**: Zero.  Affects a test.

**Original PR**: No.

**Reviewed By**: Andrew Trick ( @atrick )

**Testing**: Yes, this is a test change.

**Resolves**: rdar://118954955

Author: nate-chandler

test/SILOptimizer/OSLogMandatoryOptTest.swift

@@ -2,6 +2,8 @@
 //
 // REQUIRES: VENDOR=apple
 
+// REQUIRES: swift_stdlib_no_asserts
+
 // Tests for the OSLogOptimization pass that performs compile-time analysis
 // and optimization of the new os log APIs. The tests here check whether specific
 // compile-time constants such as the format string, the size of the byte buffer etc. are