[libj6] Create libj6

Pull syscall code out of libc and create new libj6. This should
eventually become a vDSO, but for now it can still be a static lib.
Also renames all the _syscall_* symbol names to j6_*

src/libraries/libc/arch/x86_64/_Exit.s

@@ -1,5 +1,5 @@
-extern _syscall_process_exit
+extern j6_process_exit
 global _PDCLIB_Exit
 _PDCLIB_Exit:
 	; arg should already be in rdi
-	jmp _syscall_process_exit
+	jmp j6_process_exit

src/libraries/libc/arch/x86_64/syscalls.s

@@ -1,28 +0,0 @@
-%macro SYSCALL 2
-	global _syscall_%1
-	_syscall_%1:
-		push rbp
-		mov rbp, rsp
-
-		; args should already be in rdi, etc, but rcx will
-		; get stomped, so stash it in r10, which isn't a
-		; callee-saved register, but also isn't used in the
-		; function call ABI.
-		mov r10, rcx
-
-		mov rax, %2
-		syscall
-		; result is now already in rax, so just return
-
-		pop rbp
-		ret
-%endmacro
-
-%define SYSCALL(n, name) SYSCALL name, n
-%define SYSCALL(n, name, a) SYSCALL name, n
-%define SYSCALL(n, name, a, b) SYSCALL name, n
-%define SYSCALL(n, name, a, b, c) SYSCALL name, n
-%define SYSCALL(n, name, a, b, c, d) SYSCALL name, n
-%define SYSCALL(n, name, a, b, c, d, e) SYSCALL name, n
-
-%include "j6/tables/syscalls.inc"

src/libraries/libc/include/j6libc/syscalls.h

@@ -1,15 +0,0 @@
-#pragma once
-
-#include <j6/types.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#define SYSCALL(n, name, ...) j6_status_t _syscall_ ## name (__VA_ARGS__);
-#include "j6/tables/syscalls.inc"
-#undef SYSCALL
-
-#ifdef __cplusplus
-}
-#endif

src/libraries/libc/j6libc/sbrk.c

@@ -1,6 +1,6 @@
 #include <stdint.h>
 #include <j6/errors.h>
-#include <j6libc/syscalls.h>
+#include <j6/syscalls.h>
 //void *sbrk(intptr_t) __attribute__ ((weak));
 
 static j6_handle_t __core_handle = 0;
@@ -19,7 +19,7 @@ void *sbrk(intptr_t i)
 		if (i < 0)
 			return (void*)-1;
 
-		j6_status_t result = _syscall_vma_create_map(&__core_handle, i, __core_base, 1);
+		j6_status_t result = j6_vma_create_map(&__core_handle, i, __core_base, 1);
 		if (result != j6_status_ok)
 			return (void*)-1;
 
@@ -28,7 +28,7 @@ void *sbrk(intptr_t i)
 	}
 
 	size_t new_size = __core_size + i;
-	j6_status_t result = _syscall_vma_resize(__core_handle, &new_size);
+	j6_status_t result = j6_vma_resize(__core_handle, &new_size);
 	if (result != j6_status_ok)
 		return (void*)-1;