[WebAssembly] Add tests for generic CPU config (#80775)

This adds tests for `generic` cpu configuration. We had tests for `mvp`
and `bleeding-edge` configs but not `generic`.

Author: aheejin

clang/test/Preprocessor/wasm-target-features.c

@@ -146,6 +146,26 @@
 // MVP-NOT:#define __wasm_multimemory__
 // MVP-NOT:#define __wasm_relaxed_simd__
 
+// RUN: %clang -E -dM %s -o - 2>&1 \
+// RUN:     -target wasm32-unknown-unknown -mcpu=generic \
+// RUN:   | FileCheck %s -check-prefix=GENERIC
+// RUN: %clang -E -dM %s -o - 2>&1 \
+// RUN:     -target wasm64-unknown-unknown -mcpu=generic \
+// RUN:   | FileCheck %s -check-prefix=GENERIC
+//
+// GENERIC-DAG:#define __wasm_sign_ext__ 1{{$}}
+// GENERIC-DAG:#define __wasm_mutable_globals__ 1{{$}}
+// GENERIC-NOT:#define __wasm_nontrapping_fptoint__ 1{{$}}
+// GENERIC-NOT:#define __wasm_bulk_memory__ 1{{$}}
+// GENERIC-NOT:#define __wasm_simd128__ 1{{$}}
+// GENERIC-NOT:#define __wasm_atomics__ 1{{$}}
+// GENERIC-NOT:#define __wasm_tail_call__ 1{{$}}
+// GENERIC-NOT:#define __wasm_multimemory__ 1{{$}}
+// GENERIC-NOT:#define __wasm_exception_handling__ 1{{$}}
+// GENERIC-NOT:#define __wasm_multivalue__ 1{{$}}
+// GENERIC-NOT:#define __wasm_reference_types__ 1{{$}}
+// GENERIC-NOT:#define __wasm_extended_const__ 1{{$}}
+
 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm32-unknown-unknown -mcpu=bleeding-edge \
 // RUN:   | FileCheck %s -check-prefix=BLEEDING-EDGE