[decompiler] clean up vector detection and add vector float product detection (#638)

* change

* recognize vector float product and update tests

test/decompiler/reference/kernel/dgo-h_REF.gc

@@ -42,5 +42,4 @@
   )
 
 ;; failed to figure out what this is:
-(let ((v0-4 0))
-  )
+0

test/decompiler/reference/kernel/gcommon_REF.gc

@@ -1229,5 +1229,4 @@
   )
 
 ;; failed to figure out what this is:
-(let ((v0-19 0))
-  )
+0

test/decompiler/reference/kernel/gkernel-h_REF.gc

@@ -373,5 +373,4 @@
   )
 
 ;; failed to figure out what this is:
-(let ((v0-23 0))
-  )
+0

test/decompiler/reference/kernel/gkernel_REF.gc

@@ -80,8 +80,7 @@
 (defmethod delete thread ((obj thread))
   (when (= obj (-> obj process main-thread))
    (break!)
-   (let ((v1-3 0))
-    )
+   0
    )
   (set! (-> obj process top-thread) (-> obj previous))
   (none)
@@ -140,8 +139,7 @@
      )
     )
    )
-  (let ((v0-2 0))
-   )
+  0
   (none)
   )
 
@@ -979,8 +977,7 @@
    (set! (-> obj dead-list next) (the-as dead-pool-heap-rec s5-1))
    (set! (-> s5-1 0) *null-process*)
    )
-  (let ((v0-4 0))
-   )
+  0
   (none)
   )
 
@@ -1057,8 +1054,7 @@
       (when (nonzero? s2-0)
        (when (< s2-0 0)
         (break!)
-        (let ((v1-20 0))
-         )
+        0
         )
        (shrink-heap obj s3-0)
        (relocate s3-0 (- s2-0))
@@ -1069,8 +1065,7 @@
      )
     )
    )
-  (let ((v0-8 0))
-   )
+  0
   (none)
   )
 
@@ -1123,8 +1118,7 @@
      )
     )
    )
-  (let ((v0-4 0))
-   )
+  0
   (none)
   )
 
@@ -1345,8 +1339,7 @@
     )
    (set! *listener-function* #f)
    (set! *enable-method-set* (+ *enable-method-set* -1))
-   (let ((v1-8 0))
-    )
+   0
    )
   (execute-process-tree
    *active-pool*
@@ -1850,8 +1843,7 @@
               (.lw ra-0 return-from-thread s7-0)
               (.jr ra-0)
               (nop!)
-              (let ((v1-21 0))
-               )
+              0
               )
              ((= (-> obj status) 'initialize)
               (set! (-> obj status) 'dead)
@@ -1859,8 +1851,7 @@
               )
              )
             (set! (-> obj status) 'dead)
-            (let ((v0-7 0))
-             )
+            0
             )
    (none)
    )

test/decompiler/reference/kernel/gstring-h_REF.gc

@@ -2,6 +2,4 @@
 (in-package goal)
 
 ;; failed to figure out what this is:
-(let ((v0-0 0))
-  )
-
+0

test/decompiler/reference/kernel/gstring_REF.gc

@@ -248,8 +248,7 @@
    (set! (-> str-ptr 0) (the-as uint char))
    (set! (-> str-ptr 1) (the-as uint 0))
    )
-  (let ((v1-1 0))
-   )
+  0
   0
   )
 
@@ -405,8 +404,7 @@
      )
     (set! (-> str-ptr 0) (the-as uint 0))
     )
-   (let ((v1-3 0))
-    )
+   0
    )
   #f
   )
@@ -437,8 +435,7 @@
      )
     (set! (-> ptr 1) (the-as uint 0))
     )
-   (let ((v1-7 0))
-    )
+   0
    )
   #f
   )