runtime: fix a few typos in comments

Change-Id: I07a1eb02ffc621c5696b49491181300bf411f822
Reviewed-on: https://go-review.googlesource.com/96475
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/runtime/mfixalloc.go

@@ -11,7 +11,7 @@ package runtime
 import "unsafe"
 
 // FixAlloc is a simple free-list allocator for fixed size objects.
-// Malloc uses a FixAlloc wrapped around sysAlloc to manages its
+// Malloc uses a FixAlloc wrapped around sysAlloc to manage its
 // MCache and MSpan objects.
 //
 // Memory returned by fixalloc.alloc is zeroed by default, but the

src/runtime/mgclarge.go

@@ -43,7 +43,7 @@ type treapNode struct {
 	parent    *treapNode // direct parent of this node, nil if root
 	npagesKey uintptr    // number of pages in spanKey, used as primary sort key
 	spanKey   *mspan     // span of size npagesKey, used as secondary sort key
-	priority  uint32     // random number used by treap algorithm keep tree probablistically balanced
+	priority  uint32     // random number used by treap algorithm to keep tree probabilistically balanced
 }
 
 func (t *treapNode) init() {

src/runtime/mgcmark.go

@@ -530,7 +530,7 @@ func gcAssistAlloc1(gp *g, scanWork int64) {
 		// store that clears it but an atomic check in every malloc
 		// would be a performance hit.
 		// Instead we recheck it here on the non-preemptable system
-		// stack to determine if we should preform an assist.
+		// stack to determine if we should perform an assist.
 
 		// GC is done, so ignore any remaining debt.
 		gp.gcAssistBytes = 0

src/runtime/mheap.go

@@ -561,7 +561,7 @@ retry:
 			goto retry
 		}
 		if s.sweepgen == sg-1 {
-			// the span is being sweept by background sweeper, skip
+			// the span is being swept by background sweeper, skip
 			continue
 		}
 		// already swept empty span,
@@ -751,7 +751,7 @@ func (h *mheap) allocManual(npage uintptr, stat *uint64) *mspan {
 		s.nelems = 0
 		s.elemsize = 0
 		s.limit = s.base() + s.npages<<_PageShift
-		// Manually manged memory doesn't count toward heap_sys.
+		// Manually managed memory doesn't count toward heap_sys.
 		memstats.heap_sys -= uint64(s.npages << _PageShift)
 	}
 

src/runtime/symtab.go

@@ -339,7 +339,7 @@ func (f *Func) funcInfo() funcInfo {
 
 // PCDATA and FUNCDATA table indexes.
 //
-// See funcdata.h and ../cmd/internal/obj/funcdata.go.
+// See funcdata.h and ../cmd/internal/objabi/funcdata.go.
 const (
 	_PCDATA_StackMapIndex       = 0
 	_PCDATA_InlTreeIndex        = 1