[clang] [clang][bytecode] Disable tail calls on sparc (PR #189887)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/189887

Looks like this causes problems there as well:
https://lab.llvm.org/buildbot/#/builders/114/builds/252

Interp.cpp:2572:21: error: cannot tail-call: target is not able to optimize the call into a sibling call
 2572 |   MUSTTAIL return Fn(S, PC);
      |                   ~~^~~~~~~

>From 9cbdb05c42fef4eefa3b785018b29a4db422587b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Wed, 1 Apr 2026 08:50:27 +0200
Subject: [PATCH] [clang][bytecode] Disable tail calls on sparc

Looks like this causes problems there as well:
https://lab.llvm.org/buildbot/#/builders/114/builds/252

Interp.cpp:2572:21: error: cannot tail-call: target is not able to optimize the call into a sibling call
 2572 |   MUSTTAIL return Fn(S, PC);
      |                   ~~^~~~~~~
---
 clang/lib/AST/ByteCode/Interp.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/lib/AST/ByteCode/Interp.cpp b/clang/lib/AST/ByteCode/Interp.cpp
index 0a13456e6026d..199ccf1d5a652 100644
--- a/clang/lib/AST/ByteCode/Interp.cpp
+++ b/clang/lib/AST/ByteCode/Interp.cpp
@@ -41,7 +41,7 @@ using namespace clang::interp;
 // to handle the way we use tailcalls.
 // PPC can't tail-call external calls, which is a problem for InterpNext.
 #if defined(_MSC_VER) || defined(__powerpc__) || !defined(MUSTTAIL) ||         \
-    defined(__i386__)
+    defined(__i386__) || defined(__sparc__)
 #undef MUSTTAIL
 #define MUSTTAIL
 #define USE_TAILCALLS 0