Test PR for disabling semicolon warnings (#10169)

This is another PR towards the goal of getting Z3 to compile cleanly
when included via FetchContents into clang-tidy, which uses a pretty
strict set of warnings.

https://github.com/Z3Prover/z3/pull/10020 deleted a number of
unnecessary (and, by a strict interpretation, illegal) semicolons. These
were detected by adding -Wextra-semi to CLANG_ONLY_WARNINGS during
testing. The PR did not eliminate all such unnecessary/illegal
semi-colons; Nikolaj Bjorner argued that some IDEs would be confused by
doing so for macro invocations, which otherwise look like function
calls. So it left those, and did not include adding -Wextra-semi to
CLANG_ONLY_WARNINGS in the PR.

I'm worried that not having -Wextra-semi will allow instances of the
semis we'd like to eliminate to creep back in. This PR introduces a
mechanism to disable the warnings for regions with such macro
invocations, and uses that mechanism for one file. If accepted, a
subsequent PR would use this mechanism in all the remaining places, so
that there is a clean clang build with -Wextra-semi.

I verified that:
* It compiles cleanly for if the enable/disable macros have null
definitions, as they would for non-clang compilations.
* It compiles cleanly for a clang build without -Wextra-semis.
* It compiles successfully, albeit with *many* warnings, for a clang
build with-Wextra-semis -- but none of those errors are for the regions
in ast.h where the warning is disabled.

src/util/manage_warnings.h

@@ -0,0 +1,60 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    build_warnings.h
+
+Abstract:
+
+    Macros to control compiler build warnings.
+
+Author:
+
+    Dave Detlefs 2026-07-20.
+
+Revision History:
+
+--*/
+#pragma once
+
+// #define PRAGMA_MACRO(s) _Pragma(s)
+
+// In some cases, we wish to be able to terminate macros with semicolons,
+// even when the semi is (strictly speaking) illegal when following the
+// expansion of the macro.  (The macro invocations can look like function
+// invocations to some IDE's, and the lack of a trailing semi can confuse them.)
+// In those cases, we add this DUMMY_DECL to the macro; it "consumes" the trailing
+// semi, making it legal.
+
+// Standard preprocessor concatenation gymnastics
+#define CONCAT_IMPL(x, y) x##y
+#define CONCAT(x, y) CONCAT_IMPL(x, y)
+
+#define DUMMY_DECL using CONCAT(__dummy_decl_, __COUNTER__) = int
+
+#define DO_PRAGMA(x) _Pragma(#x)
+
+#ifdef __clang__
+
+#define START_DISABLE_WARNING(s)		\
+  _Pragma("clang diagnostic push")		\
+  DO_PRAGMA(clang diagnostic ignored #s)
+
+
+#define END_DISABLE_WARNING			\
+  _Pragma("clang diagnostic pop")		\
+  DUMMY_DECL
+
+#define START_DISABLE_EXTRA_SEMI_WARNING START_DISABLE_WARNING(-Wextra-semi)
+
+#else
+
+#define START_DISABLE_EXTRA_SEMI_WARNING
+#define END_DISABLE_WARNING
+
+#endif
+
+
+
+