workaround for preprocessor bug in pcc

with this patch, musl compiles and mostly works with pcc 1.0.0. a few
tests are still failing and i'm uncertain whether they are due to
portability problems in musl, or bugs in pcc, but i suspect the
latter.

src/internal/syscall.h

@@ -8,13 +8,13 @@
 #define socketcall __socketcall
 #define socketcall_cp __socketcall_cp
 
-#define __syscall_cp0(n) __syscall_cp(n,0,0,0,0,0,0)
+#define __syscall_cp0(n) (__syscall_cp)(n,0,0,0,0,0,0)
-#define __syscall_cp1(n,a) __syscall_cp(n,(long)(a),0,0,0,0,0)
+#define __syscall_cp1(n,a) (__syscall_cp)(n,(long)(a),0,0,0,0,0)
-#define __syscall_cp2(n,a,b) __syscall_cp(n,(long)(a),(long)(b),0,0,0,0)
+#define __syscall_cp2(n,a,b) (__syscall_cp)(n,(long)(a),(long)(b),0,0,0,0)
-#define __syscall_cp3(n,a,b,c) __syscall_cp(n,(long)(a),(long)(b),(long)(c),0,0,0)
+#define __syscall_cp3(n,a,b,c) (__syscall_cp)(n,(long)(a),(long)(b),(long)(c),0,0,0)
-#define __syscall_cp4(n,a,b,c,d) __syscall_cp(n,(long)(a),(long)(b),(long)(c),(long)(d),0,0)
+#define __syscall_cp4(n,a,b,c,d) (__syscall_cp)(n,(long)(a),(long)(b),(long)(c),(long)(d),0,0)
-#define __syscall_cp5(n,a,b,c,d,e) __syscall_cp(n,(long)(a),(long)(b),(long)(c),(long)(d),(long)(e),0)
+#define __syscall_cp5(n,a,b,c,d,e) (__syscall_cp)(n,(long)(a),(long)(b),(long)(c),(long)(d),(long)(e),0)
-#define __syscall_cp6(n,a,b,c,d,e,f) __syscall_cp(n,(long)(a),(long)(b),(long)(c),(long)(d),(long)(e),(long)(f))
+#define __syscall_cp6(n,a,b,c,d,e,f) (__syscall_cp)(n,(long)(a),(long)(b),(long)(c),(long)(d),(long)(e),(long)(f))
 
 long (__syscall_cp)(long, long, long, long, long, long, long);