Fix CI on develop after #5585 (#5779)

* Fix CI on develop after #5585

- test-diagnostics-optimized: -O3 makes GCC's -Winline and
  -Wsuggest-attribute=pure/const warnings fire with the ci_test_gcc flag
  set; turn them off for this test.
- test-diagnostics-optimized: suppress Clang's -Wexit-time-destructors for
  the static table in to_json.
- Infer: raise pulse-max-disjuncts from 20 to 40. With the default,
  Pulse loses the stored type in basic_json::replace_value() and reports
  false null dereferences of get_ptr() results in unit-pointer_access.cpp.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Ignore Infer's false USE_AFTER_DELETE in ordered_map::erase

Infer's std::string model keeps the buffer of a moved-from string, so the
destroy-and-reconstruct loop in erase(first, last) looks like it destroys a
buffer twice.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Mark throw_on_discarded()'s parameters as used without exceptions

With JSON_NOEXCEPTION, JSON_THROW expands to std::abort(), so Clang's
-Wunused-parameter breaks test-disabled_exceptions (since #5761).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Skip the span_input_adapter sax_parse checks with deleted deprecated functions

The #5676 regression test (#5740) calls the deprecated
sax_parse(span_input_adapter&&, ...), which JSON_DELETE_DEPRECATED_FUNCTIONS
deletes, so ci_test_delete_deprecated_functions failed to build.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Fall back to the first entry in test-diagnostics-optimized's to_json

clang-tidy (clang-analyzer-security.ArrayBound) flagged it->second for a
value not in the table. Use the same fallback as
NLOHMANN_JSON_SERIALIZE_ENUM; the test still fails with -Werror=array-bounds
on the headers from before #5585.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Fix clang-tidy findings in tests from #5762 and #5774

- unit-regression2.cpp (#5762): const/auto for the destroy() test values;
  NOLINT the intended copy in check_destroy_edge_case().
- unit-serialization.cpp (#5774): build the expected strings with += instead
  of chained operator+ (performance-inefficient-string-concatenation).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

tests/src/unit-regression2.cpp

@@ -1035,7 +1035,7 @@ TEST_CASE("regression test #5135 - destructor never allocates, even under memory
         failing_allocator_allocations = 0;
         failing_allocator_deallocations = 0;
         {
-            failing_json j = failing_json::array(
+            const failing_json j = failing_json::array(
             {
                 failing_json::array({1, 2}),
                 failing_json::object({{"key", failing_json::array({3})}})
@@ -1052,7 +1052,7 @@ TEST_CASE("regression test #5135 - destructor never allocates, even under memory
     {
         std::size_t allocations_before = 0;
         {
-            failing_json j = make_deep_nest<failing_json>(100000, false);
+            const auto j = make_deep_nest<failing_json>(100000, false);
             allocations_before = failing_allocator_allocations;
             fail_next_allocation = true;
         }
@@ -1066,7 +1066,7 @@ TEST_CASE("regression test #5135 - destructor never allocates, even under memory
     {
         std::size_t allocations_before = 0;
         {
-            failing_json j = make_deep_nest<failing_json>(100000, true);
+            const auto j = make_deep_nest<failing_json>(100000, true);
             allocations_before = failing_allocator_allocations;
             fail_next_allocation = true;
         }
@@ -1080,7 +1080,7 @@ TEST_CASE("regression test #5135 - destructor never allocates, even under memory
     {
         std::size_t allocations_before = 0;
         {
-            failing_ordered_json j = make_deep_nest<failing_ordered_json>(100000, true);
+            const auto j = make_deep_nest<failing_ordered_json>(100000, true);
             allocations_before = failing_allocator_allocations;
             fail_next_allocation = true;
         }
@@ -1138,7 +1138,7 @@ BasicJsonType make_single_chain(std::size_t depth)
 template<class BasicJsonType>
 void check_destroy_edge_case(const BasicJsonType& value)
 {
-    const BasicJsonType copy = value;
+    const BasicJsonType copy = value; // NOLINT(performance-unnecessary-copy-initialization): the copy is the point
     CHECK(copy == value);
 }
 } // namespace
@@ -1183,7 +1183,7 @@ TEST_CASE_TEMPLATE("regression test #5135 - destroy() edge cases", BasicJsonType
 
     SECTION("single-element chain, 1000 levels deep")
     {
-        BasicJsonType root = make_single_chain<BasicJsonType>(1000);
+        auto root = make_single_chain<BasicJsonType>(1000);
         check_destroy_edge_case(root);
     }
 
@@ -1220,7 +1220,7 @@ TEST_CASE_TEMPLATE("regression test #5135 - destroy() edge cases", BasicJsonType
 
     SECTION("destruction via assignment on a deep tree")
     {
-        BasicJsonType root = make_single_chain<BasicJsonType>(2000);
+        auto root = make_single_chain<BasicJsonType>(2000);
         // assigning a new value destroys the old one in place
         root = nullptr;
         CHECK(root.is_null());