On linux the clang exectuable might be clang-20. Fix match.

Author: bd1976bris

clang/test/Driver/DTLTO/dtlto.c

@@ -21,7 +21,7 @@
 
 // FORWARD: ld.lld
 // FORWARD-SAME: "--thinlto-distributor=d.exe"
-// FORWARD-SAME: "--thinlto-remote-compiler={{.*}}clang{{(.exe)?}}"
+// FORWARD-SAME: "--thinlto-remote-compiler={{.*}}clang{{[^\"]*}}"
 // FORWARD-SAME: "--thinlto-distributor-arg=a1"
 // FORWARD-SAME: "--thinlto-distributor-arg=a2"
 // FORWARD-SAME: "--thinlto-distributor-arg=a3"
@@ -46,7 +46,7 @@
 
 // DEFAULT: ld.lld
 // DEFAULT-SAME: "--thinlto-distributor=d.exe"
-// DEFAULT-SAME: "--thinlto-remote-compiler={{.*}}clang{{(.exe)?}}"
+// DEFAULT-SAME: "--thinlto-remote-compiler={{.*}}clang{{[^\"]*}}"
 
 /// Check that nothing is forwarded when the compiler is not in LTO mode, and that
 /// appropriate unused option warnings are issued.