Kernel/LibC: Add crt* files to LibC and remove crt0 from kernel

There was no reason for libc get crt0 from kernel.

kernel/arch/x86_64/crt0.S

@@ -1,34 +0,0 @@
-.section .text
-
-.global _start
-_start:
-	# Set up end of the stack frame linked list.
-	movq $0, %rbp
-	pushq %rbp # rip=0
-	pushq %rbp # rbp=0
-	movq %rsp, %rbp
-
-	# We need those in a moment when we call main.
-	pushq %rdx
-	pushq %rsi
-	pushq %rdi
-
-	# Prepare signals, memory allocation, stdio and such.
-	movq %rdx, %rdi
-	call _init_libc
-
-	# Run the global constructors.
-	call _init
-
-	# Restore argc and argv.
-	popq %rdi
-	popq %rsi
-	popq %rdx
-
-	# Run main
-	call main
-
-	# Terminate the process with the exit code.
-	movl %eax, %edi
-	call exit
-.size _start, . - _start