[clang] [clang][analyzer] Add StoreToImmutable checker (PR #150417)

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+// RUN: %clang_analyze_cc1 -analyzer-checker=alpha.core.StoreToImmutable -verify %s
+
+// Test basic functionality of StoreToImmutable checker
+// This tests direct writes to immutable regions without function modeling
+
+// Direct write to a const global variable
+const int global_const = 42; // expected-note {{Memory region is in immutable space}}
+
+void test_direct_write_to_const_global() {
+  // This should trigger a warning about writing to immutable memory
+  *(int*)&global_const = 100; // expected-warning {{Writing to immutable memory is undefined behavior}}
+  // expected-note at -1 {{Writing to immutable memory is undefined behavior. This memory region is marked as immutable and should not be modified}}
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gamesh411 wrote:

The expected-notes are alive, at near latest versions, when running the lit tests, the substitution for `%clang_analyze_cc1` does indeed have the flag `-analyzer-output=text`. Plus it would be nice to assert the note tag that signifies the position of the declared position of the immutable variable declaration, so I would rather keep the notes in the test.

https://github.com/llvm/llvm-project/pull/150417