cmd/internal/src: fix a few typos in documentation

Noticed while reading recent commits.

Change-Id: Ibcd500b0ea5732364124572a17b374402d715090
Reviewed-on: https://go-review.googlesource.com/c/go/+/170059
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Author: josharian

src/cmd/internal/src/pos.go

@@ -301,11 +301,11 @@ type lico uint32
 // The bitfield order is chosen to make IsStmt be the least significant
 // part of a position; its use is to communicate statement edges through
 // instruction scrambling in code generation, not to impose an order.
-// TODO: Prologue and epilogue are perhaps better handled as psuedoops for the assembler,
+// TODO: Prologue and epilogue are perhaps better handled as pseudo-ops for the assembler,
 // because they have almost no interaction with other uses of the position.
 const (
 	lineBits, lineMax     = 20, 1<<lineBits - 2
-	bogusLine             = 1<<lineBits - 1 // Not a line number; used to disruopt infinite loops
+	bogusLine             = 1<<lineBits - 1 // Not a line number; used to disrupt infinite loops
 	isStmtBits, isStmtMax = 2, 1<<isStmtBits - 1
 	xlogueBits, xlogueMax = 2, 1<<xlogueBits - 1
 	colBits, colMax       = 32 - lineBits - xlogueBits - isStmtBits, 1<<colBits - 1