langref: add missing comma in assembly expressions

doc/langref.html.in

@@ -7457,20 +7457,20 @@ pub const STDOUT_FILENO = 1;
 
 pub fn syscall1(number: usize, arg1: usize) usize {
     return asm volatile ("syscall"
-        : [ret] "={rax}" (-> usize)
+        : [ret] "={rax}" (-> usize),
         : [number] "{rax}" (number),
-          [arg1] "{rdi}" (arg1)
+          [arg1] "{rdi}" (arg1),
         : "rcx", "r11"
     );
 }
 
 pub fn syscall3(number: usize, arg1: usize, arg2: usize, arg3: usize) usize {
     return asm volatile ("syscall"
-        : [ret] "={rax}" (-> usize)
+        : [ret] "={rax}" (-> usize),
         : [number] "{rax}" (number),
           [arg1] "{rdi}" (arg1),
           [arg2] "{rsi}" (arg2),
-          [arg3] "{rdx}" (arg3)
+          [arg3] "{rdx}" (arg3),
         : "rcx", "r11"
     );
 }
@@ -7519,14 +7519,14 @@ pub fn syscall1(number: usize, arg1: usize) usize {
     // type is the result type of the inline assembly expression.
     // If it is a value binding, then `%[ret]` syntax would be used
     // to refer to the register bound to the value.
-        (-> usize)
+        (-> usize),
     // Next is the list of inputs.
     // The constraint for these inputs means, "when the assembly code is
     // executed, $rax shall have the value of `number` and $rdi shall have
     // the value of `arg1`". Any number of input parameters is allowed,
     // including none.
         : [number] "{rax}" (number),
-            [arg1] "{rdi}" (arg1)
+            [arg1] "{rdi}" (arg1),
     // Next is the list of clobbers. These declare a set of registers whose
     // values will not be preserved by the execution of this assembly code.
     // These do not include output or input registers. The special clobber