Remove FunctionType (#2510)

Function signatures were previously redundantly stored on Function
objects as well as on FunctionType objects. These two signature
representations had to always be kept in sync, which was error-prone
and needlessly complex. This PR takes advantage of the new ability of
Type to represent multiple value types by consolidating function
signatures as a pair of Types (params and results) stored on the
Function object.

Since there are no longer module-global named function types,
significant changes had to be made to the printing and emitting of
function types, as well as their parsing and manipulation in various
passes.

The C and JS APIs and their tests also had to be updated to remove
named function types.

1 files changed, 11 insertions, 12 deletions

diff --git a/test/passes/remove-unused-brs_shrink-level=1.txt b/test/passes/remove-unused-brs_shrink-level=1.txt
index 5d17a7688..e05b66040 100644
--- a/test/passes/remove-unused-brs_shrink-level=1.txt
+++ b/test/passes/remove-unused-brs_shrink-level=1.txt
@@ -1,9 +1,8 @@
 (module
- (type $0 (func (param i32)))
- (type $1 (func))
- (type $2 (func (result i32)))
+ (type $none_=>_i32 (func (result i32)))
+ (type $none_=>_none (func))
  (memory $0 256 256)
- (func $b14 (; 0 ;) (type $2) (result i32)
+ (func $b14 (; 0 ;) (result i32)
   (drop
    (select
     (block $block1 (result i32)
@@ -45,7 +44,7 @@
   )
   (i32.const 0)
  )
- (func $join-br_ifs (; 1 ;) (type $1)
+ (func $join-br_ifs (; 1 ;)
   (block $out
    (br_if $out
     (i32.or
@@ -123,7 +122,7 @@
    )
   )
  )
- (func $join-and-it-becomes-unreachable (; 2 ;) (type $1)
+ (func $join-and-it-becomes-unreachable (; 2 ;)
   (block $label$1
    (block $block
     (br_if $label$1
@@ -139,7 +138,7 @@
    )
   )
  )
- (func $br-if-unreachable-pair (; 3 ;) (type $1)
+ (func $br-if-unreachable-pair (; 3 ;)
   (block $label$14
    (br_if $label$14
     (unreachable)
@@ -149,7 +148,7 @@
    )
   )
  )
- (func $br-if-unreachable-pair2 (; 4 ;) (type $1)
+ (func $br-if-unreachable-pair2 (; 4 ;)
   (block $label$14
    (br_if $label$14
     (i32.const 0)
@@ -159,7 +158,7 @@
    )
   )
  )
- (func $simple-switch (; 5 ;) (type $2) (result i32)
+ (func $simple-switch (; 5 ;) (result i32)
   (block $A
    (block $B
     (block $y
@@ -180,7 +179,7 @@
   )
   (i32.const 3)
  )
- (func $simple-switch-2 (; 6 ;) (type $2) (result i32)
+ (func $simple-switch-2 (; 6 ;) (result i32)
   (local $0 i32)
   (block $A
    (block $B
@@ -214,7 +213,7 @@
   )
   (i32.const 3)
  )
- (func $simple-switch-3 (; 7 ;) (type $2) (result i32)
+ (func $simple-switch-3 (; 7 ;) (result i32)
   (local $0 i32)
   (block $A
    (block $B
@@ -247,7 +246,7 @@
   )
   (i32.const 3)
  )
- (func $simple-switch-4 (; 8 ;) (type $2) (result i32)
+ (func $simple-switch-4 (; 8 ;) (result i32)
   (block $A
    (block $B
     (block $y