stage2: more progress moving `zig cc` to stage2

 * std.cache_hash exposes Hasher type
 * std.cache_hash makes hasher_init a global const
 * std.cache_hash supports cloning so that clones can share the same
   open manifest dir handle as well as fork from shared hasher state
 * start to populate the cache_hash for stage2 builds
 * remove a footgun from std.cache_hash add function
 * get rid of std.Target.ObjectFormat.unknown
 * rework stage2 logic for resolving output artifact names by adding
   object_format as an optional parameter to std.zig.binNameAlloc
 * support -Denable-llvm in stage2 tests
 * Module supports the use case when there are no .zig files
 * introduce c_object_table and failed_c_objects to Module
 * propagate many new kinds of data from CLI into Module and into
   linker.Options
 * introduce -fLLVM, -fLLD, -fClang and their -fno- counterparts.
   closes #6251.
   - add logic for choosing when to use LLD or zig's self-hosted linker
 * stub code for implementing invoking Clang to build C objects
 * add -femit-h, -femit-h=foo, and -fno-emit-h CLI options

1 files changed, 1 insertions, 0 deletions

diff --git a/build.zig b/build.zig
index 43b3b7eebf..d3846fbdf8 100644
--- a/build.zig
+++ b/build.zig
@@ -139,6 +139,7 @@ pub fn build(b: *Builder) !void {
     const is_wasmtime_enabled = b.option(bool, "enable-wasmtime", "Use Wasmtime to enable and run WASI libstd tests") orelse false;
     const glibc_multi_dir = b.option([]const u8, "enable-foreign-glibc", "Provide directory with glibc installations to run cross compiled tests that link glibc");
 
+    test_stage2.addBuildOption(bool, "have_llvm", enable_llvm);
     test_stage2.addBuildOption(bool, "enable_qemu", is_qemu_enabled);
     test_stage2.addBuildOption(bool, "enable_wine", is_wine_enabled);
     test_stage2.addBuildOption(bool, "enable_wasmtime", is_wasmtime_enabled);