[linux] add debug-trap for __debugbreak wrapping. Copied from:

https://github.com/nemequ/portable-snippets/blob/84abba93ff3d52c87e08ba81de1cc6615a42b72e/debug-trap/debug-trap.h

extern/portable-snippets/COPYING.md

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extern/portable-snippets/debug-trap.h

@@ -0,0 +1,83 @@
+/* Debugging assertions and traps
+ * Portable Snippets - https://github.com/nemequ/portable-snippets
+ * Created by Evan Nemerson <evan@nemerson.com>
+ *
+ *   To the extent possible under law, the authors have waived all
+ *   copyright and related or neighboring rights to this code.  For
+ *   details, see the Creative Commons Zero 1.0 Universal license at
+ *   https://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+#if !defined(PSNIP_DEBUG_TRAP_H)
+#define PSNIP_DEBUG_TRAP_H
+
+#if !defined(PSNIP_NDEBUG) && defined(NDEBUG) && !defined(PSNIP_DEBUG)
+#  define PSNIP_NDEBUG 1
+#endif
+
+#if defined(__has_builtin) && !defined(__ibmxl__)
+#  if __has_builtin(__builtin_debugtrap)
+#    define psnip_trap() __builtin_debugtrap()
+#  elif __has_builtin(__debugbreak)
+#    define psnip_trap() __debugbreak()
+#  endif
+#endif
+#if !defined(psnip_trap)
+#  if defined(_MSC_VER) || defined(__INTEL_COMPILER)
+#    define psnip_trap() __debugbreak()
+#  elif defined(__ARMCC_VERSION)
+#    define psnip_trap() __breakpoint(42)
+#  elif defined(__ibmxl__) || defined(__xlC__)
+#    include <builtins.h>
+#    define psnip_trap() __trap(42)
+#  elif defined(__DMC__) && defined(_M_IX86)
+     static inline void psnip_trap(void) { __asm int 3h; }
+#  elif defined(__i386__) || defined(__x86_64__)
+     static inline void psnip_trap(void) { __asm__ __volatile__("int3"); }
+#  elif defined(__thumb__)
+     static inline void psnip_trap(void) { __asm__ __volatile__(".inst 0xde01"); }
+#  elif defined(__aarch64__)
+     static inline void psnip_trap(void) { __asm__ __volatile__(".inst 0xd4200000"); }
+#  elif defined(__arm__)
+     static inline void psnip_trap(void) { __asm__ __volatile__(".inst 0xe7f001f0"); }
+#  elif defined (__alpha__) && !defined(__osf__)
+     static inline void psnip_trap(void) { __asm__ __volatile__("bpt"); }
+#  elif defined(_54_)
+     static inline void psnip_trap(void) { __asm__ __volatile__("ESTOP"); }
+#  elif defined(_55_)
+     static inline void psnip_trap(void) { __asm__ __volatile__(";\n .if (.MNEMONIC)\n ESTOP_1\n .else\n ESTOP_1()\n .endif\n NOP"); }
+#  elif defined(_64P_)
+     static inline void psnip_trap(void) { __asm__ __volatile__("SWBP 0"); }
+#  elif defined(_6x_)
+     static inline void psnip_trap(void) { __asm__ __volatile__("NOP\n .word 0x10000000"); }
+#  elif defined(__STDC_HOSTED__) && (__STDC_HOSTED__ == 0) && defined(__GNUC__)
+#    define psnip_trap() __builtin_trap()
+#  else
+#    include <signal.h>
+#    if defined(SIGTRAP)
+#      define psnip_trap() raise(SIGTRAP)
+#    else
+#      define psnip_trap() raise(SIGABRT)
+#    endif
+#  endif
+#endif
+
+#if defined(HEDLEY_LIKELY)
+#  define PSNIP_DBG_LIKELY(expr) HEDLEY_LIKELY(expr)
+#elif defined(__GNUC__) && (__GNUC__ >= 3)
+#  define PSNIP_DBG_LIKELY(expr) __builtin_expect(!!(expr), 1)
+#else
+#  define PSNIP_DBG_LIKELY(expr) (!!(expr))
+#endif
+
+#if !defined(PSNIP_NDEBUG) || (PSNIP_NDEBUG == 0)
+#  define psnip_dbg_assert(expr) do { \
+    if (!PSNIP_DBG_LIKELY(expr)) { \
+      psnip_trap(); \
+    } \
+  } while (0)
+#else
+#  define psnip_dbg_assert(expr)
+#endif
+
+#endif /* !defined(PSNIP_DEBUG_TRAP_H) */