Add latest WASM proposal support

[tolauwae]

100 files from the official spectests fail due to changes from newly standardized WASM proposals:

• [x] block.wast
• [x] br_if.wast
• [ ] br_table.wast
• [x] br.wast
• [ ] call_indirect.wast
• [ ] call.wast
• [ ] conversions.wast
• [ ] endianness.wast
• [ ] fac.wast
• [ ] float_literals.wast
• [ ] float_memory.wast
• [ ] func_ptrs.wast
• [ ] func.wast
• [ ] global.wast
• [ ] i32.wast
• [ ] i64.wast
• [ ] if.wast
• [ ] int_exprs.wast
• [x] load.wast
• [x] local_get.wast
• [x] local_set.wast
• [x] local_tee.wast
• [ ] loop.wast
• [ ] memory_init.wast
• [ ] memory_fill.wast
• [ ] memory_grow.wast
• [ ] memory_redundancy.wast
• [x] memory_size.wast
• [ ] memory_trap.wast
• [x] nop.wast
• [ ] ref_is_null.wast
• [ ] ref_null.wast
• [x] return.wast
• [ ] select.wast
• [ ] simd_address.wast
• [ ] simd_bit_shift.wast
• [ ] simd_bitwise.wast
• [ ] simd_boolean.wast
• [ ] simd_conversions.wast
• [ ] simd_f32x4_arith.wast
• [ ] simd_f32x4.wast
• [ ] simd_f32x4_cmp.wast
• [ ] simd_f32x4_pmin_pmax.wast
• [ ] simd_f32x4_rounding.wast
• [ ] simd_f64x2_arith.wast
• [ ] simd_f64x2.wast
• [ ] simd_f64x2_cmp.wast
• [ ] simd_f64x2_pmin_pmax.wast
• [ ] simd_f64x2_rounding.wast
• [ ] simd_i16x8_arith2.wast
• [ ] simd_i16x8_arith.wast
• [ ] simd_i16x8_cmp.wast
• [ ] simd_i16x8_extadd_pairwise_i8x16.wast
• [ ] simd_i16x8_extmul_i8x16.wast
• [ ] simd_i16x8_q15mulr_sat_s.wast
• [ ] simd_i16x8_sat_arith.wast
• [ ] simd_i32x4_arith2.wast
• [ ] simd_i32x4_arith.wast
• [ ] simd_i32x4_cmp.wast
• [ ] simd_i32x4_dot_i16x8.wast
• [ ] simd_i32x4_extadd_pairwise_i16x8.wast
• [ ] simd_i32x4_extmul_i16x8.wast
• [ ] simd_i32x4_trunc_sat_f32x4.wast
• [ ] simd_i32x4_trunc_sat_f64x2.wast
• [ ] simd_i64x2_arith2.wast
• [ ] simd_i64x2_arith.wast
• [ ] simd_i64x2_cmp.wast
• [ ] simd_i64x2_extmul_i32x4.wast
• [ ] simd_i8x16_arith2.wast
• [ ] simd_i8x16_arith.wast
• [ ] simd_i8x16_cmp.wast
• [ ] simd_i8x16_sat_arith.wast
• [ ] simd_int_to_int_extend.wast
• [ ] simd_lane.wast
• [ ] simd_load16_lane.wast
• [ ] simd_load32_lane.wast
• [ ] simd_load64_lane.wast
• [ ] simd_load8_lane.wast
• [ ] simd_load.wast
• [ ] simd_load_extend.wast
• [ ] simd_load_splat.wast
• [ ] simd_load_zero.wast
• [ ] simd_splat.wast
• [ ] simd_store16_lane.wast
• [ ] simd_store32_lane.wast
• [ ] simd_store64_lane.wast
• [ ] simd_store8_lane.wast
• [ ] simd_store.wast
• [ ] skip-stack-guard-page.wast
• [ ] start.wast
• [x] store.wast
• [ ] table_fill.wast
• [ ] table_get.wast
• [ ] table_grow.wast
• [ ] table_set.wast
• [ ] table_size.wast
• [ ] traps.wast
• [ ] unreachable.wast
• [ ] unreached-valid.wast
• [ ] unwind.wast

[tolauwae]

Currently, 23384/25975 (90%) of failing tests are tests for the SIMD proposal.