newlib: Avoid introducing ESP-IDF macros from newlib platform headers

Also, rewrite the assert.h header to be clearer

Closes https://github.com/espressif/esp-idf/issues/6445

components/newlib/platform_include/assert.h

@@ -19,23 +19,28 @@
 #pragma once
 #include <sdkconfig.h>
 #include <stdlib.h>
-#include "esp_compiler.h"
 
 #include_next <assert.h>
 
-#if defined(CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_SILENT) && !defined(NDEBUG)
+/* moved part of libc provided assert to here allows
-    #undef assert
+ * tweaking the assert macro to use __builtin_expect()
-    #define assert(__e) (likely(__e)) ? (void)0 : abort()
+ * and reduce jumps in the "asserts OK" code path
-#else
+ *
-    /* moved part of toolchain provided assert to there then
+ * Note: using __builtin_expect() not likely() to avoid defining the likely
-     * we can tweak the original assert macro to perform likely
+ * macro in namespace of non-IDF code that may include this standard header.
-     * before deliver it to original toolchain implementation
  */
 #undef assert
-    #ifdef NDEBUG
+
+#if defined(NDEBUG)
+
 # define assert(__e) ((void)0)
-    #else
+
-    # define assert(__e) (likely(__e) ? (void)0 : __assert_func (__FILE__, __LINE__, \
+#elif CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_SILENT
+
+#define assert(__e) __builtin_expect(!!(__e), 1) ? (void)0 : abort()
+
+#else // !CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_SILENT
+
+#define assert(__e) (__builtin_expect(!!(__e), 1) ? (void)0 : __assert_func (__FILE__, __LINE__, \
                                                                              __ASSERT_FUNC, #__e))
 #endif
-#endif