Remove heaps from core Cranelift, push them into cranelift-wasm (#5386)

* cranelift-wasm: translate Wasm loads into lower-level CLIF operations

Rather than using `heap_{load,store,addr}`.

* cranelift: Remove the `heap_{addr,load,store}` instructions

These are now legalized in the `cranelift-wasm` frontend.

* cranelift: Remove the `ir::Heap` entity from CLIF

* Port basic memory operation tests to .wat filetests

* Remove test for verifying CLIF heaps

* Remove `heap_addr` from replace_branching_instructions_and_cfg_predecessors.clif test

* Remove `heap_addr` from readonly.clif test

* Remove `heap_addr` from `table_addr.clif` test

* Remove `heap_addr` from the simd-fvpromote_low.clif test

* Remove `heap_addr` from simd-fvdemote.clif test

* Remove `heap_addr` from the load-op-store.clif test

* Remove the CLIF heap runtest

* Remove `heap_addr` from the global_value.clif test

* Remove `heap_addr` from fpromote.clif runtests

* Remove `heap_addr` from fdemote.clif runtests

* Remove `heap_addr` from memory.clif parser test

* Remove `heap_addr` from reject_load_readonly.clif test

* Remove `heap_addr` from reject_load_notrap.clif test

* Remove `heap_addr` from load_readonly_notrap.clif test

* Remove `static-heap-without-guard-pages.clif` test

Will be subsumed when we port `make-heap-load-store-tests.sh` to generating
`.wat` tests.

* Remove `static-heap-with-guard-pages.clif` test

Will be subsumed when we port `make-heap-load-store-tests.sh` over to `.wat`
tests.

* Remove more heap tests

These will be subsumed by porting `make-heap-load-store-tests.sh` over to `.wat`
tests.

* Remove `heap_addr` from `simple-alias.clif` test

* Remove `heap_addr` from partial-redundancy.clif test

* Remove `heap_addr` from multiple-blocks.clif test

* Remove `heap_addr` from fence.clif test

* Remove `heap_addr` from extends.clif test

* Remove runtests that rely on heaps

Heaps are not a thing in CLIF or the interpreter anymore

* Add generated load/store `.wat` tests

* Enable memory-related wasm features in `.wat` tests

* Remove CLIF heap from fcmp-mem-bug.clif test

* Add a mode for compiling `.wat` all the way to assembly in filetests

* Also generate WAT to assembly tests in `make-load-store-tests.sh`

* cargo fmt

* Reinstate `f{de,pro}mote.clif` tests without the heap bits

* Remove undefined doc link

* Remove outdated SVG and dot file from docs

* Add docs about `None` returns for base address computation helpers

* Factor out `env.heap_access_spectre_mitigation()` to a local

* Expand docs for `FuncEnvironment::heaps` trait method

* Restore f{de,pro}mote+load clif runtests with stack memory

cranelift/filetests/filetests/isa/aarch64/heap_addr.clif

@@ -1,88 +0,0 @@
-test compile precise-output
-set unwind_info=false
-set enable_heap_access_spectre_mitigation=true
-target aarch64
-
-function %dynamic_heap_check(i64 vmctx, i32) -> i64 {
-    gv0 = vmctx
-    gv1 = load.i64 notrap aligned gv0
-    heap0 = dynamic gv0, bound gv1, offset_guard 0x1000, index_type i32
-
-block0(v0: i64, v1: i32):
-    v2 = heap_addr.i64 heap0, v1, 0, 0
-    return v2
-}
-
-; block0:
-;   mov w8, w1
-;   ldr x9, [x0]
-;   mov x9, x9
-;   add x10, x0, x1, UXTW
-;   movz x7, #0
-;   subs xzr, x8, x9
-;   csel x0, x7, x10, hi
-;   csdb
-;   ret
-
-function %static_heap_check(i64 vmctx, i32) -> i64 {
-    gv0 = vmctx
-    heap0 = static gv0, bound 0x1_0000, offset_guard 0x1000, index_type i32
-
-block0(v0: i64, v1: i32):
-    v2 = heap_addr.i64 heap0, v1, 0, 0
-    return v2
-}
-
-; block0:
-;   mov w6, w1
-;   add x7, x0, x1, UXTW
-;   movz x5, #0
-;   subs xzr, x6, #65536
-;   csel x0, x5, x7, hi
-;   csdb
-;   ret
-
-function %dynamic_heap_check_with_offset(i64 vmctx, i32) -> i64 {
-    gv0 = vmctx
-    gv1 = load.i64 notrap aligned gv0
-    heap0 = dynamic gv0, bound gv1, offset_guard 0x1000, index_type i32
-
-block0(v0: i64, v1: i32):
-    v2 = heap_addr.i64 heap0, v1, 16, 8
-    return v2
-}
-
-; block0:
-;   mov w10, w1
-;   movz x9, #24
-;   adds x11, x10, x9
-;   b.lo 8 ; udf
-;   ldr x12, [x0]
-;   add x13, x0, x1, UXTW
-;   add x13, x13, #16
-;   movz x10, #0
-;   subs xzr, x11, x12
-;   csel x0, x10, x13, hi
-;   csdb
-;   ret
-
-function %static_heap_check_with_offset(i64 vmctx, i32) -> i64 {
-    gv0 = vmctx
-    heap0 = static gv0, bound 0x1_0000, offset_guard 0x1000, index_type i32
-
-block0(v0: i64, v1: i32):
-    v2 = heap_addr.i64 heap0, v1, 16, 8
-    return v2
-}
-
-; block0:
-;   mov w8, w1
-;   add x9, x0, x1, UXTW
-;   add x9, x9, #16
-;   movz x6, #65512
-;   movz x10, #0
-;   subs xzr, x8, x6
-;   csel x0, x10, x9, hi
-;   csdb
-;   ret
-