[clang] [clang] Fix --entry command line option (PR #69114)

[Sergei Barannikov via cfe-commits]

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@@ -20,3 +20,10 @@
 // Make sure that we do warn in other cases.
 // RUN: %clang %s -lfoo -c -o %t/tmp2.o -### 2>&1 | FileCheck %s --check-prefix=UNUSED
 // UNUSED: warning:{{.*}}unused
+
+// Make sure -e and its aliases --entry and --entry= are properly passed on.
+// RUN: %clang -### -target x86_64-unknown-linux-gnu --entry test %s 2>&1 | FileCheck --check-prefix=ENTRY %s
+// RUN: %clang -### -target x86_64-unknown-linux-gnu --entry=test %s 2>&1 | FileCheck --check-prefix=ENTRY %s
+// RUN: %clang -### -target x86_64-unknown-linux-gnu -etest %s 2>&1 | FileCheck --check-prefix=ENTRY %s
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s-barannikov wrote:

Re: CI failure
gcc accepts both `-etest` and `-e test`. Currently, we support only the second variant. If we want to support the first variant, the `def e` should be changed to `JoinedOrSeparate`. If we don't, this line should be changed to pass `-e test`.


https://github.com/llvm/llvm-project/pull/69114