Use c"lit" for CStrings without unwrap

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -148,7 +148,7 @@ fn prepare_lto(
     // __llvm_profile_counter_bias is pulled in at link time by an undefined reference to
     // __llvm_profile_runtime, therefore we won't know until link time if this symbol
     // should have default visibility.
-    symbols_below_threshold.push(CString::new("__llvm_profile_counter_bias").unwrap());
+    symbols_below_threshold.push(c"__llvm_profile_counter_bias".to_owned());
     Ok((symbols_below_threshold, upstream_modules))
 }
 

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -509,7 +509,7 @@ fn get_pgo_sample_use_path(config: &ModuleConfig) -> Option<CString> {
 }
 
 fn get_instr_profile_output_path(config: &ModuleConfig) -> Option<CString> {
-    config.instrument_coverage.then(|| CString::new("default_%m_%p.profraw").unwrap())
+    config.instrument_coverage.then(|| c"default_%m_%p.profraw".to_owned())
 }
 
 pub(crate) unsafe fn llvm_optimize(