Inline jump tables in parsed br_table instructions (#5755)

As jump tables are used by at most one br_table instruction, inline their definition in those instructions instead of requiring them to be declared as function-level metadata.

cranelift/reader/src/lexer.rs

@@ -41,7 +41,6 @@ pub enum Token<'a> {
     DynamicStackSlot(u32), // dss4
     GlobalValue(u32),      // gv3
     Table(u32),            // table2
-    JumpTable(u32),        // jt2
     Constant(u32),         // const2
     FuncRef(u32),          // fn2
     SigRef(u32),           // sig2
@@ -346,7 +345,6 @@ impl<'a> Lexer<'a> {
             "dt" => Some(Token::DynamicType(number)),
             "gv" => Some(Token::GlobalValue(number)),
             "table" => Some(Token::Table(number)),
-            "jt" => Some(Token::JumpTable(number)),
             "const" => Some(Token::Constant(number)),
             "fn" => Some(Token::FuncRef(number)),
             "sig" => Some(Token::SigRef(number)),