Remove support for no-system-llvm

Also add tests for min-system-llvm-version.

src/tools/compiletest/src/header.rs

@@ -1109,9 +1109,6 @@ fn ignore_lldb(config: &Config, line: &str) -> IgnoreDecision {
 }
 
 fn ignore_llvm(config: &Config, line: &str) -> IgnoreDecision {
-    if config.system_llvm && line.starts_with("no-system-llvm") {
-        return IgnoreDecision::Ignore { reason: "ignored when the system LLVM is used".into() };
-    }
     if let Some(needed_components) =
         config.parse_name_value_directive(line, "needs-llvm-components")
     {

src/tools/compiletest/src/header/tests.rs

@@ -242,15 +242,6 @@ fn aux_build() {
     );
 }
 
-#[test]
-fn no_system_llvm() {
-    let config: Config = cfg().system_llvm(false).build();
-    assert!(!check_ignore(&config, "// no-system-llvm"));
-
-    let config: Config = cfg().system_llvm(true).build();
-    assert!(check_ignore(&config, "// no-system-llvm"));
-}
-
 #[test]
 fn llvm_version() {
     let config: Config = cfg().llvm_version("8.1.2").build();
@@ -266,6 +257,18 @@ fn llvm_version() {
     assert!(!check_ignore(&config, "// min-llvm-version: 9.0"));
 }
 
+#[test]
+fn system_llvm_version() {
+    let config: Config = cfg().system_llvm(true).llvm_version("17.0.0").build();
+    assert!(check_ignore(&config, "// min-system-llvm-version: 18.0"));
+
+    let config: Config = cfg().system_llvm(true).llvm_version("18.0.0").build();
+    assert!(!check_ignore(&config, "// min-system-llvm-version: 18.0"));
+
+    let config: Config = cfg().llvm_version("17.0.0").build();
+    assert!(!check_ignore(&config, "// min-system-llvm-version: 18.0"));
+}
+
 #[test]
 fn ignore_target() {
     let config: Config = cfg().target("x86_64-unknown-linux-gnu").build();