[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/j6/include/j6/syscalls.h

@@ -6,7 +6,7 @@
 extern "C" {
 #endif
 
-#define SYSCALL(n, name, ...) j6_status_t _syscall_ ## name (__VA_ARGS__);
+#define SYSCALL(n, name, ...) j6_status_t j6_ ## name (__VA_ARGS__);
 #include "j6/tables/syscalls.inc"
 #undef SYSCALL
 

src/libraries/j6/syscalls.s

@@ -1,6 +1,6 @@
 %macro SYSCALL 2
-	global _syscall_%1
-	_syscall_%1:
+	global j6_%1
+	j6_%1:
 		push rbp
 		mov rbp, rsp
 

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/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;