fix(tinygo): syntax error when field name is 'type' in record and a function exists that uses that record

[rajatjindal]

This PR fixes generator for go when:

• world has a keyword as name
• record has a field with keyword as name AND that record is used in a function

in addition, it added following two testcases which worked without any explicit changes:

• interface has keyword
• enum has keyword

an example of failure can be seen below. Notice lift_ret_ptr.type in the below generated code, here type is a golang keyword. and thus fails.

error:

<standard input>:25:11: expected selector or type assertion, found 'type'
test types ... FAILED

generated code:

    if lift_ret_ptr.type == 0 {
      lift_ret_val_Type = WasiFilesystem0_2_0_TypesDescriptorTypeUnknown()
    }

[alexcrichton]

Nice, thanks!