[WebAssembly] Update generic and bleeding-edge CPUs

This updates the list of features in 'generic' and 'bleeding-edge' CPUs
in the backend to match
https://github.com/llvm/llvm-project/blob/4e0a0eae58f7a6998866719f7eb970096a2a52e9/clang/lib/Basic/Targets/WebAssembly.cpp#L150-L175.

It is hard to add a backend test for this, given that we don't have a
convenient way of testing the list of features included in each cpu like
the preprocessor test in Clang:
https://github.com/llvm/llvm-project/blob/4e0a0eae58f7a6998866719f7eb970096a2a52e9/clang/test/Preprocessor/wasm-target-features.c#L158-L208
And the current features for 'generic' and 'bleeding-edge' don't have a
separate backend test anyway.

Author: aheejin

llvm/lib/Target/WebAssembly/WebAssembly.td

@@ -110,13 +110,17 @@ def : ProcessorModel<"mvp", NoSchedModel, []>;
 // consideration given to available support in relevant engines and tools, and
 // the importance of the features.
 def : ProcessorModel<"generic", NoSchedModel,
-                      [FeatureSignExt, FeatureMutableGlobals]>;
+                      [FeatureMultivalue, FeatureMutableGlobals,
+                       FeatureReferenceTypes, FeatureSignExt]>;
 
 // Latest and greatest experimental version of WebAssembly. Bugs included!
 def : ProcessorModel<"bleeding-edge", NoSchedModel,
-                      [FeatureSIMD128, FeatureAtomics,
-                       FeatureNontrappingFPToInt, FeatureSignExt,
-                       FeatureMutableGlobals, FeatureBulkMemory,
+                      [FeatureAtomics, FeatureBulkMemory,
+                       FeatureExceptionHandling, FeatureExtendedConst,
+                       FeatureHalfPrecision, FeatureMultiMemory,
+                       FeatureMultivalue, FeatureMutableGlobals,
+                       FeatureNontrappingFPToInt, FeatureRelaxedSIMD,
+                       FeatureReferenceTypes, FeatureSIMD128, FeatureSignExt,
                        FeatureTailCall]>;
 
 //===----------------------------------------------------------------------===//