Add ARRAY_API_TESTS_VERBOSE_SPECIAL_CASES environment variable

When ARRAY_API_TESTS_VERBOSE_SPECIAL_CASES=1 is set, the parser emits
each special case line during parsing in the format:
"SPEC_CASE: function_name: special_case_line"

This allows real-time tracking of special cases during test runs with:
ARRAY_API_TESTS_VERBOSE_SPECIAL_CASES=1 ARRAY_API_TESTS_MODULE=array_api_strict pytest array_api_tests/test_special_cases.py -s

Changes:
- Added _VERBOSE_SPECIAL_CASES flag based on environment variable
- Modified parse_unary_case_block() to emit SPEC_CASE lines when enabled
- Modified parse_binary_case_block() to emit SPEC_CASE lines when enabled

Co-authored-by: ev-br <2133832+ev-br@users.noreply.github.com>

Author: Copilot

array_api_tests/test_special_cases.py

@@ -15,6 +15,7 @@
 import inspect
 import math
 import operator
+import os
 import re
 from dataclasses import dataclass, field
 from decimal import ROUND_HALF_EVEN, Decimal
@@ -35,6 +36,9 @@
 from . import xp, xps
 from .stubs import category_to_funcs
 
+# Check if verbose special case logging is enabled
+_VERBOSE_SPECIAL_CASES = os.environ.get("ARRAY_API_TESTS_VERBOSE_SPECIAL_CASES") == "1"
+
 UnaryCheck = Callable[[float], bool]
 BinaryCheck = Callable[[float, float], bool]
 
@@ -879,6 +883,10 @@ def parse_unary_case_block(case_block: str, func_name: str, record_list: Optiona
         if record_list is not None:
             record_list.append(f"{func_name}: {case_str}.")
 
+        # Emit the special case line if verbose mode is enabled
+        if _VERBOSE_SPECIAL_CASES:
+            print(f"SPEC_CASE: {func_name}: {case_str}.")
+        
 
         # Try to parse complex cases if we're in the complex section
         if in_complex_section and (m := r_complex_case.search(case_str)):
@@ -1386,6 +1394,10 @@ def parse_binary_case_block(case_block: str, func_name: str, record_list: Option
         if record_list is not None:
             record_list.append(f"{func_name}: {case_str}.")
 
+        # Emit the special case line if verbose mode is enabled
+        if _VERBOSE_SPECIAL_CASES:
+            print(f"SPEC_CASE: {func_name}: {case_str}.")
+        
         if r_redundant_case.search(case_str):
             continue
         if r_binary_case.match(case_str):