[LLDB][NativePDB] Add local constant support (#180612)

This is mostly to support Swift `let`, but I found a way to get MSVC to
emit a local `S_CONSTANT` (see test).

I saw the note about `MakeConstantLocalExpression` at
https://github.com/llvm/llvm-project/blob/2e34fecf02962e4c8477ca88cc5ac9386a0f76bb/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp#L2177
but couldn't repro with local or global (emitted as `S_LDATA32` in both
cases).

1 files changed, 24 insertions, 0 deletions

diff --git a/lldb/test/Shell/SymbolFile/NativePDB/local-constant.test b/lldb/test/Shell/SymbolFile/NativePDB/local-constant.test
new file mode 100644
index 000000000000..83d376312a29
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/NativePDB/local-constant.test
@@ -0,0 +1,24 @@
+# REQUIRES: msvc
+
+# Test that we can display local S_CONSTANT records.
+# MSVC emits S_CONSTANT for static const locals; clang-cl does not.
+# RUN: split-file %s %t
+# RUN: %build --compiler=msvc --nodefaultlib -o %t.exe -- %t/main.cpp
+# RUN: %lldb -f %t.exe -s %t/commands.input 2>&1 | FileCheck %s
+
+#--- main.cpp
+
+int main() {
+  static const int kConstant = 42;
+  return kConstant;
+}
+
+#--- commands.input
+
+settings set stop-line-count-after 0
+break set -n main
+run
+frame variable
+quit
+
+# CHECK: (const int) {{.*}}kConstant = 42