linker: fix build-obj and -fno-emit-bin

This commit fixes two problems:

* `zig build-obj` regressed from the cache-mode branch. It would crash
  because it assumed that dirname on the emit bin path would not be
  null. This assumption was invalid when outputting to the current
  working directory - a pretty common use case for `zig build-obj`.

* When using the LLVM backend, `-fno-emit-bin` combined with any other
  kind of emitting, such as `-femit-asm`, emitted nothing.

Both issues are now fixed.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/glibc.zig b/src/glibc.zig
index 4424cb9b90..65ee88ed81 100644
--- a/src/glibc.zig
+++ b/src/glibc.zig
@@ -225,7 +225,7 @@ pub fn buildCRTFile(comp: *Compilation, crt_file: CRTFile) !void {
             });
         },
         .scrt1_o => {
-            const start_os: Compilation.CSourceFile = blk: {
+            const start_o: Compilation.CSourceFile = blk: {
                 var args = std.ArrayList([]const u8).init(arena);
                 try add_include_dirs(comp, arena, &args);
                 try args.appendSlice(&[_][]const u8{
@@ -266,7 +266,7 @@ pub fn buildCRTFile(comp: *Compilation, crt_file: CRTFile) !void {
                     .extra_flags = args.items,
                 };
             };
-            return comp.build_crt_file("Scrt1", .Obj, &[_]Compilation.CSourceFile{ start_os, abi_note_o });
+            return comp.build_crt_file("Scrt1", .Obj, &[_]Compilation.CSourceFile{ start_o, abi_note_o });
         },
         .libc_nonshared_a => {
             const target = comp.getTarget();