stage2: passing threadlocal tests for x86_64-linux

 * use the real start code for LLVM backend with x86_64-linux
   - there is still a check for zig_backend after initializing the TLS
     area to skip some stuff.
 * introduce new AIR instructions and implement them for the LLVM
   backend. They are the same as `call` except with a modifier.
   - call_always_tail
   - call_never_tail
   - call_never_inline
 * LLVM backend calls hasRuntimeBitsIgnoringComptime in more places to
   avoid unnecessarily depending on comptimeOnly being resolved for some
   types.
 * LLVM backend: remove duplicate code for setting linkage and value
   name. The canonical place for this is in `updateDeclExports`.
 * LLVM backend: do some assembly template massaging to make `%%`
   rendered as `%`. More hacks will be needed to make inline assembly
   catch up with stage1.

1 files changed, 8 insertions, 2 deletions

diff --git a/test/behavior/basic.zig b/test/behavior/basic.zig
index f925ddede3..f22e93008c 100644
--- a/test/behavior/basic.zig
+++ b/test/behavior/basic.zig
@@ -720,6 +720,11 @@ test "string concatenation" {
 
 test "thread local variable" {
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_llvm and builtin.cpu.arch != .x86_64) return error.SkipZigTest; // TODO
 
     const S = struct {
         threadlocal var t: i32 = 1234;
@@ -746,11 +751,12 @@ fn maybe(x: bool) anyerror!?u32 {
 }
 
 test "pointer to thread local array" {
-    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_llvm and builtin.cpu.arch != .x86_64) return error.SkipZigTest; // TODO
 
     const s = "Hello world";
     std.mem.copy(u8, buffer[0..], s);