chore(iast): optimize iast by migrating should_iast_patch function to c

ddtrace/appsec/_iast/__init__.py

@@ -92,11 +92,6 @@ def enable_iast_propagation():
     global _iast_propagation_enabled
     if _iast_propagation_enabled:
         return
-    # We need to preload the package_distributions because if we call importlib_metadata inside a module hook
-    # it raises a circular-import
-    from ddtrace.internal.packages import get_package_distributions
-
-    get_package_distributions()
 
     log.debug("iast::instrumentation::starting IAST")
     ModuleWatchdog.register_pre_exec_module_hook(_should_iast_patch, _exec_iast_patched_module)

ddtrace/appsec/_iast/_ast/CMakeLists.txt

@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.10)
+project(iastpatch C)
+
+find_package(Python3 REQUIRED COMPONENTS Development)
+
+add_library(iastpatch MODULE iastpatch.c)
+
+target_include_directories(iastpatch PRIVATE ${Python3_INCLUDE_DIRS})
+
+target_link_libraries(iastpatch PRIVATE ${Python3_LIBRARIES})
+
+set_target_properties(iastpatch PROPERTIES LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_LIST_DIR}")