zig cc: integration with sysroot arg (#10568)

Prior to this change, even if the use specified the sysroot on the
compiler line like so

```
zig cc --sysroot=/path/to/sdk
```

it would only be used as a prefix to include paths and not as a prefix
for `zig ld` linker.

1 files changed, 4 insertions, 0 deletions

diff --git a/tools/update_clang_options.zig b/tools/update_clang_options.zig
index 7360f96560..73b1bbd284 100644
--- a/tools/update_clang_options.zig
+++ b/tools/update_clang_options.zig
@@ -412,6 +412,10 @@ const known_options = [_]KnownOpt{
         .name = "emit-llvm",
         .ident = "emit_llvm",
     },
+    .{
+        .name = "sysroot",
+        .ident = "sysroot",
+    },
 };
 
 const blacklisted_options = [_][]const u8{};