[wasmprinter] support custom indent text

[oovm]

Close #1962

[oovm]

It seems that '\t' is not supported, so I agree to use --indent

;; RUN: print --indent-text '\t' %

---- "tests/cli\\print-custom-indent-text.wat" ----
failed test "tests/cli\\print-custom-indent-text.wat"

Caused by:
    0: failed RUN directive `` on line 1
    1: failed to check stdout expectation (auto-update with BLESS=1)
    2: failed test: result is not as expected:Diff < left / right > :
        (module
       <        (type (;0;) (func (param i32) (result i32)))
       <        (func (;0;) (type 0) (param i32) (result i32)
       <                local.get 0
       <        )
       <        (export "f" (func 0))
       >'/t'(type (;0;) (func (param i32) (result i32)))
       >'/t'(export "f" (func 0))
       >'/t'(func (;0;) (type 0) (param i32) (result i32)
       >'/t''/t'local.get 0
       >'/t')
        )

failures:
    "tests/cli\\print-custom-indent-text.wat"

test result: FAILED. 125 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 10.92s

---

Very strange, spaces are not supported either.

;; RUN: print --indent-text "    " %

---- "tests/cli\\print-custom-indent-text.wat" ----
failed test "tests/cli\\print-custom-indent-text.wat"

Caused by:
    0: failed RUN directive `` on line 1
    1: "E:\\RustroverProjects\\wasm-tools\\target\\debug\\wasm-tools.exe" "print" "--indent-text" "\"" "\"" "tests/cli\\print-custom-indent-text.wat" failed:
                    status: exit code: 2
                    stdout:
                    stderr: error: unexpected argument 'tests/cli\print-custom-indent-text.wat' found

[oovm]

It seems that run_test has some problems, and does not support strings and escapes, whether it is \t, '\t' or " "

[alexcrichton]

Thanks!

[alexcrichton]

Oh sorry, yes it's ok to not test \t or " " directly, the parser for these tests is pretty primitive. You could also test --indent-text xxxx and that'll assert "xxxx" starts each line