cmd/compile: fix trivial typos in comments

Change-Id: I04880d87e317a1140ec12da6ec5e788991719760
Reviewed-on: https://go-review.googlesource.com/114936Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/compile/internal/ssa/branchelim.go

@@ -4,7 +4,7 @@
 
 package ssa
 
-// branchelim tries to elminiate branches by
+// branchelim tries to eliminate branches by
 // generating CondSelect instructions.
 //
 // Search for basic blocks that look like

src/cmd/compile/internal/ssa/gen/generic.rules

@@ -212,7 +212,7 @@
 // (Mod64u x y) is always between 0 (inclusive) and y (exclusive).
 (IsInBounds (Mod32u _ y) y) -> (ConstBool [1])
 (IsInBounds (Mod64u _ y) y) -> (ConstBool [1])
-// Right shifting a unsigned number limits its value.
+// Right shifting an unsigned number limits its value.
 (IsInBounds (ZeroExt8to64  (Rsh8Ux64  _ (Const64 [c]))) (Const64 [d])) && 0 < c && c <  8 && 1<<uint( 8-c)-1 < d -> (ConstBool [1])
 (IsInBounds (ZeroExt8to32  (Rsh8Ux64  _ (Const64 [c]))) (Const32 [d])) && 0 < c && c <  8 && 1<<uint( 8-c)-1 < d -> (ConstBool [1])
 (IsInBounds (ZeroExt8to16  (Rsh8Ux64  _ (Const64 [c]))) (Const16 [d])) && 0 < c && c <  8 && 1<<uint( 8-c)-1 < d -> (ConstBool [1])