start: Fix ++ usage in inline asm string construction.

Author: alexrp

lib/std/start.zig

@@ -277,15 +277,16 @@ fn _start() callconv(.Naked) noreturn {
             ,
             // zig fmt: off
             .csky =>
-            if (builtin.position_independent_code)
+            (if (builtin.position_independent_code)
                 // The CSKY ABI assumes that `gb` is set to the address of the GOT in order for
                 // position-independent code to work. We depend on this in `std.os.linux.start_pie`
                 // to locate `_DYNAMIC` as well.
                 \\ grs t0, 1f
                 \\ 1:
                 \\ lrw gb, 1b@GOTPC
                 \\ addu gb, t0
-            else ""
+                \\
+            else "")
             ++
             \\ movi lr, 0
             \\ mov a0, sp
@@ -311,7 +312,7 @@ fn _start() callconv(.Naked) noreturn {
             // zig fmt: off
             .riscv32, .riscv64 =>
             // The self-hosted riscv64 backend is not able to assemble this yet.
-            if (builtin.zig_backend != .stage2_riscv64)
+            (if (builtin.zig_backend != .stage2_riscv64)
                 // The RISC-V ELF ABI assumes that `gp` is set to the value of `__global_pointer$` at
                 // startup in order for GP relaxation to work, even in static builds.
                 \\ .weak __global_pointer$
@@ -320,7 +321,8 @@ fn _start() callconv(.Naked) noreturn {
                 \\ .option norelax
                 \\ lla gp, __global_pointer$
                 \\ .option pop
-            else ""
+                \\
+            else "")
             ++
             \\ li s0, 0
             \\ li ra, 0