stage2: progress towards ability to compile compiler-rt

 * prepare compiler-rt to support being compiled by stage2
   - put in a few minor workarounds that will be removed later, such as
     using `builtin.stage2_arch` rather than `builtin.cpu.arch`.
   - only try to export a few symbols for now - we'll move more symbols
     over to the "working in stage2" section as they become functional
     and gain test coverage.
   - use `inline fn` at function declarations rather than `@call` with an
     always_inline modifier at the callsites, to avoid depending on the
     anonymous array literal syntax language feature (for now).
 * AIR: replace floatcast instruction with fptrunc and fpext for
   shortening and widening floating point values, respectively.
 * Introduce a new ZIR instruction, `export_value`, which implements
   `@export` for the case when the thing to be exported is a local
   comptime value that points to a function.
   - AstGen: fix `@export` not properly reporting ambiguous decl
     references.
 * Sema: handle ExportOptions linkage. The value is now available to all
   backends.
   - Implement setting global linkage as appropriate in the LLVM
     backend. I did not yet inspect the LLVM IR, so this still needs to
     be audited. There is already a pending task to make sure the alias
     stuff is working as intended, and this is related.
   - Sema almost handles section, just a tiny bit more code is needed in
     `resolveExportOptions`.
 * Sema: implement float widening and shortening for both `@floatCast`
   and float coercion.
   - Implement the LLVM backend code for this as well.

1 files changed, 2 insertions, 2 deletions

diff --git a/test/behavior.zig b/test/behavior.zig
index f328db968e..7fbba99a8c 100644
--- a/test/behavior.zig
+++ b/test/behavior.zig
@@ -13,6 +13,7 @@ test {
     _ = @import("behavior/atomics.zig");
     _ = @import("behavior/sizeof_and_typeof.zig");
     _ = @import("behavior/translate_c_macros.zig");
+    _ = @import("behavior/union.zig");
     _ = @import("behavior/widening.zig");
 
     if (builtin.zig_is_stage2) {
@@ -149,7 +150,7 @@ test {
         _ = @import("behavior/typename.zig");
         _ = @import("behavior/undefined.zig");
         _ = @import("behavior/underscore.zig");
-        _ = @import("behavior/union.zig");
+        _ = @import("behavior/union_stage1.zig");
         _ = @import("behavior/usingnamespace_stage1.zig");
         _ = @import("behavior/var_args.zig");
         _ = @import("behavior/vector.zig");
@@ -158,7 +159,6 @@ test {
             _ = @import("behavior/wasm.zig");
         }
         _ = @import("behavior/while.zig");
-        _ = @import("behavior/widening_stage1.zig");
         _ = @import("behavior/src.zig");
         _ = @import("behavior/translate_c_macros_stage1.zig");
     }