[clang] [NFCI][analyzer] Regularize NodeBuilder classes (PR #180960)

[Donát Nagy via cfe-commits]

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@@ -0,0 +1,83 @@
+// RUN: %clang_analyze_cc1 -verify %s -analyzer-checker=core
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NagyDonat wrote:

This concept is named `IndirectGoto` in the codebase (e.g. `IndirectGotoNodeBuilder`, `IndirectGotoStmtClass` etc.), that's why I prefer not adding `computed`. WDYT about this? 

I added `basics` to clarify that this only tests basic functionality, but on a second thought I'm not that attached to it -- maybe it would be better to remove it from the names of both test files.

https://github.com/llvm/llvm-project/pull/180960