Optimize Mathf.pow for size (#1199)

Author: MaxGraey

std/assembly/math.ts

@@ -2,9 +2,7 @@
  (type $none_=>_none (func))
  (type $f32_=>_f32 (func (param f32) (result f32)))
  (type $f64_=>_f64 (func (param f64) (result f64)))
- (memory $0 1)
- (data (i32.const 1025) "\01\00\00\01\00\00\00\03\00\00\00\00\01\00\00\be\f3\f8y\eca\f6?\190\96[\c6\fe\de\bf=\88\afJ\edq\f5?\a4\fc\d42h\0b\db\bf\b0\10\f0\f09\95\f4?{\b7\1f\n\8bA\d7\bf\85\03\b8\b0\95\c9\f3?{\cfm\1a\e9\9d\d3\bf\a5d\88\0c\19\0d\f3?1\b6\f2\f3\9b\1d\d0\bf\a0\8e\0b{\"^\f2?\f0z;\1b\1d|\c9\bf?4\1aJJ\bb\f1?\9f<\af\93\e3\f9\c2\bf\ba\e5\8a\f0X#\f1?\\\8dx\bf\cb`\b9\bf\a7\00\99A?\95\f0?\ce_G\b6\9do\aa\bf\00\00\00\00\00\00\f0?\00\00\00\00\00\00\00\00\acG\9a\fd\8c`\ee?=\f5$\9f\ca8\b3?\a0j\02\1f\b3\a4\ec?\ba\918T\a9v\c4?\e6\fcjW6 \eb?\d2\e4\c4J\0b\84\ce?-\aa\a1c\d1\c2\e9?\1ce\c6\f0E\06\d4?\edAx\03\e6\86\e8?\f8\9f\1b,\9c\8e\d8?bHS\f5\dcg\e7?\cc{\b1N\a4\e0\dc?")
- (data (i32.const 1297) "\01\00\00\01\00\00\00\04\00\00\00\00\01\00\00\00\00\00\00\00\00\f0?t\85\15\d3\b0\d9\ef?\0f\89\f9lX\b5\ef?Q[\12\d0\01\93\ef?{Q}<\b8r\ef?\aa\b9h1\87T\ef?8bunz8\ef?\e1\de\1f\f5\9d\1e\ef?\15\b71\n\fe\06\ef?\cb\a9:7\a7\f1\ee?\"4\12L\a6\de\ee?-\89a`\08\ce\ee?\'*6\d5\da\bf\ee?\82O\9dV+\b4\ee?)TH\dd\07\ab\ee?\85U:\b0~\a4\ee?\cd;\7ff\9e\a0\ee?t_\ec\e8u\9f\ee?\87\01\ebs\14\a1\ee?\13\ceL\99\89\a5\ee?\db\a0*B\e5\ac\ee?\e5\c5\cd\b07\b7\ee?\90\f0\a3\82\91\c4\ee?]%>\b2\03\d5\ee?\ad\d3Z\99\9f\e8\ee?G^\fb\f2v\ff\ee?\9cR\85\dd\9b\19\ef?i\90\ef\dc 7\ef?\87\a4\fb\dc\18X\ef?_\9b{3\97|\ef?\da\90\a4\a2\af\a4\ef?@En[v\d0\ef?")
+ (memory $0 0)
  (global $binary/b (mut i32) (i32.const 0))
  (global $binary/i (mut i32) (i32.const 0))
  (global $binary/I (mut i64) (i64.const 0))

tests/compiler/binary.optimized.wat

@@ -1809,6 +1809,7 @@
    local.get $17
    f32.demote_f64
   end
+  return
  )
  (func $~lib/math/NativeMath.mod (; 3 ;) (param $0 f64) (param $1 f64) (result f64)
   (local $2 i64)