major restructuring, prepare for smp

code/user/personalities/posix/posix_path.h

@@ -0,0 +1,16 @@
+#pragma once
+// posix_path.h - POSIX <-> native path translation
+
+// SYNTHETIC sentinel returned from PosixTranslatePath for /dev/null and
+// /dev/zero; the caller must handle these before passing to any syscall.
+#define SYNTH_DEVNULL  "\x01<devnull>"
+#define SYNTH_DEVZERO  "\x01<devzero>"
+
+// Translate a POSIX path to a native kernel path.
+// Returns a pointer to 'out' on success, or SYNTH_DEVNULL / SYNTH_DEVZERO
+// for those synthetic devices. 'out' must be at least 512 bytes.
+const char* PosixTranslatePath(const char* in, char* out, size_t outSize);
+
+// Translate a native kernel path back to a POSIX-style path.
+// Strips the drive letter prefix and flips backslashes.
+void NativeToPosix(const char* in, char* out, size_t outSize);