[clang] [clang] model WASM alloca addrspaces in Sema (PR #197540)

[Demetrius Kanios via cfe-commits]

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@@ -55,6 +55,7 @@ static const LangASMap FakeAddrSpaceMap = {
     18, // hlsl_output
     19, // hlsl_push_constant
     20, // wasm_funcref
+    21, // wasm_externref
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QuantumSegfault wrote:

A bit confused on two things. 

- Why is `wasm_externef` being added rather than `wasm_var`? What is the purpose of `FakeAddrSpaceMap`
- What do the values mean? Because `wasm_funcref` is indeed 20, but `wasm_externref` is 10, not 21

https://github.com/llvm/llvm-project/pull/197540