Migrate most *.wasm tests to *.wat (bytecodealliance#212)

* Support `*.wat` suffixes for tests

* Delete wasm tests that are duplicates of `*.wast`

This commit was generate by a script where all `*.wasm` modules were
extracted from `*.wast` files, and then any exact duplicate checked in
`*.wasm` files were deleted which matched. This way there should be less
duplication between `*.wasm` and `*.wast` tests.

* Remove all remaining wast-extracted wasm modules

Now that wast files are run directly there's no need to duplicate the
tests with these modules.

* Convert some `*.wasm` files to `*.wat`

Author: alexcrichton

Cargo.toml

@@ -16,6 +16,7 @@ anyhow = "1.0"
 criterion = "0.3"
 getopts = "0.2"
 wast = "15.0.0"
+wat = "1.0.16"
 rayon = "1.3"
 
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