Convert tail call tests from Makefile to proper codegen test

- Remove old Makefile-based test in tests/run-make/tail-call-llvm-ir/
- Add new codegen test in tests/codegen/tail-call-become.rs
- Tests verify that 'become' generates LLVM tail call instructions
- Tests also verify that regular calls don't generate tail calls

Author: semtexzv

rmetaQZcwdq/full.rmeta

@@ -0,0 +1,56 @@
+//@ compile-flags: -C opt-level=0 -Cpanic=abort
+//@ needs-llvm-components: x86
+
+#![feature(explicit_tail_calls)]
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @with_tail
+pub fn with_tail(n: u32) -> u32 {
+    // CHECK: tail call noundef i32 @{{.*}}with_tail{{.*}}(i32 noundef %{{.*}})
+    if n == 0 { 0 } else { become with_tail(n - 1) }
+}
+
+// CHECK-LABEL: @no_tail
+pub fn no_tail(n: u32) -> u32 {
+    // CHECK-NOT: tail call
+    // CHECK: call noundef i32 @{{.*}}no_tail{{.*}}(i32 noundef %{{.*}})
+    if n == 0 { 0 } else { no_tail(n - 1) }
+}
+
+// CHECK-LABEL: @even_with_tail
+pub fn even_with_tail(n: u32) -> bool {
+    // CHECK: tail call noundef {{.*}} @{{.*}}odd_with_tail{{.*}}(i32 noundef %{{.*}})
+    match n {
+        0 => true,
+        _ => become odd_with_tail(n - 1),
+    }
+}
+
+// CHECK-LABEL: @odd_with_tail
+pub fn odd_with_tail(n: u32) -> bool {
+    // CHECK: tail call noundef {{.*}} @{{.*}}even_with_tail{{.*}}(i32 noundef %{{.*}})
+    match n {
+        0 => false,
+        _ => become even_with_tail(n - 1),
+    }
+}
+
+// CHECK-LABEL: @even_no_tail
+pub fn even_no_tail(n: u32) -> bool {
+    // CHECK-NOT: tail call
+    // CHECK: call noundef {{.*}} @{{.*}}odd_no_tail{{.*}}(i32 noundef %{{.*}})
+    match n {
+        0 => true,
+        _ => odd_no_tail(n - 1),
+    }
+}
+
+// CHECK-LABEL: @odd_no_tail
+pub fn odd_no_tail(n: u32) -> bool {
+    // CHECK-NOT: tail call
+    // CHECK: call noundef {{.*}} @{{.*}}even_no_tail{{.*}}(i32 noundef %{{.*}})
+    match n {
+        0 => false,
+        _ => even_no_tail(n - 1),
+    }
+}