Mark gcc-<version/triplet> as gcc in Unix CC toolchain

Previously only gcc-binaries named exactly `gcc` were marked as `gcc`,
with the others being marked as `compiler`.

Fixes #17794

tools/cpp/unix_cc_configure.bzl

@@ -273,7 +273,15 @@ def _is_clang(repository_ctx, cc):
 def _is_gcc(repository_ctx, cc):
     # GCC's version output uses the basename of argv[0] as the program name:
     # https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/gcc.cc;h=158461167951c1b9540322fb19be6a89d6da07fc;hb=HEAD#l8728
-    return repository_ctx.execute([cc, "--version"]).stdout.startswith("gcc ")
+    cc_argv0 = repository_ctx.execute([cc, "--version"]).stdout.partition(" ")[0]
+    if cc_argv0 == "gcc":
+        return True
+
+    # Program names like gcc-11 and gcc-arm-non-eabi.
+    if cc_argv0.startswith("gcc-"):
+        return True
+
+    return False
 
 def _get_compiler_name(repository_ctx, cc):
     if _is_clang(repository_ctx, cc):