Fix a bunch of typos

--
MOS_MIGRATED_REVID=138757881
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
index 08614ac..fffacb6 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
@@ -94,7 +94,7 @@
    * is closed, it becomes immutable, including the Frame, which can be shared in other
    * {@link Environment}-s. Indeed, a {@link UserDefinedFunction} will close over the global
    * Frame of its definition {@link Environment}, which will thus be reused (immutably)
-   * in all any {@link Environment} in which this function is called, so it's important to
+   * in any {@link Environment} in which this function is called, so it's important to
    * preserve the {@link Mutability} to make sure no Frame is modified after it's been finalized.
    */
   public static final class Frame implements Freezable {
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/LValue.java b/src/main/java/com/google/devtools/build/lib/syntax/LValue.java
index ccd28f5..02f6084 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/LValue.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/LValue.java
@@ -101,7 +101,7 @@
     if (o instanceof SkylarkDict) {
       SkylarkDict<Object, Object> dict = (SkylarkDict<Object, Object>) o;
       dict.put(key, value, loc, env);
-    } else if (o instanceof  SkylarkList) {
+    } else if (o instanceof SkylarkList) {
       SkylarkList<Object> list = (SkylarkList<Object>) o;
       list.set(key, value, loc, env);
     } else {
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Mutability.java b/src/main/java/com/google/devtools/build/lib/syntax/Mutability.java
index 44b3605..21d5c28 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Mutability.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Mutability.java
@@ -236,8 +236,8 @@
 
     // Consider an {@link Environment} e1, in which is created {@link UserDefinedFunction} f1,
     // that closes over some variable v1 bound to list l1. If somehow, via the magic of callbacks,
-    // f1 or l1 is passed as argument to some function f2 evaluated in {@link environment} e2
-    // while e1 is be mutable, e2, being a different {@link Environment}, should not be
+    // f1 or l1 is passed as an argument to some function f2 evaluated in {@link Environment} e2
+    // while e1 is still mutable, then e2, being a different {@link Environment}, should not be
     // allowed to mutate objects from e1. It's a bug, that shouldn't happen in our current code
     // base, so we throw an AssertionError. If in the future such situations are allowed to happen,
     // then we should throw a MutabilityException instead.