Fix merge lexical environment to *always* respect prologue statements (#24602) (#24654)

Author: weswigham

src/compiler/visitor.ts

@@ -1468,7 +1468,7 @@ namespace ts {
         }
 
         return isNodeArray(statements)
-            ? setTextRange(createNodeArray(concatenate(declarations, statements)), statements)
+            ? setTextRange(createNodeArray(prependStatements(statements.slice(), declarations)), statements)
             : prependStatements(statements, declarations);
     }
 

tests/baselines/reference/destructuringTempOccursAfterPrologue.js

@@ -0,0 +1,12 @@
+//// [destructuringTempOccursAfterPrologue.ts]
+function test(p: any) {
+    'use strict';
+    p = { prop: p } = p;
+}
+
+//// [destructuringTempOccursAfterPrologue.js]
+function test(p) {
+    'use strict';
+    var _a;
+    p = (_a = p, p = _a.prop, _a);
+}

tests/baselines/reference/destructuringTempOccursAfterPrologue.symbols

@@ -0,0 +1,12 @@
+=== tests/cases/compiler/destructuringTempOccursAfterPrologue.ts ===
+function test(p: any) {
+>test : Symbol(test, Decl(destructuringTempOccursAfterPrologue.ts, 0, 0))
+>p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
+
+    'use strict';
+    p = { prop: p } = p;
+>p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
+>prop : Symbol(prop, Decl(destructuringTempOccursAfterPrologue.ts, 2, 9))
+>p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
+>p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
+}

tests/baselines/reference/destructuringTempOccursAfterPrologue.types

@@ -0,0 +1,17 @@
+=== tests/cases/compiler/destructuringTempOccursAfterPrologue.ts ===
+function test(p: any) {
+>test : (p: any) => void
+>p : any
+
+    'use strict';
+>'use strict' : "use strict"
+
+    p = { prop: p } = p;
+>p = { prop: p } = p : any
+>p : any
+>{ prop: p } = p : any
+>{ prop: p } : { prop: any; }
+>prop : any
+>p : any
+>p : any
+}

tests/cases/compiler/destructuringTempOccursAfterPrologue.ts

@@ -0,0 +1,4 @@
+function test(p: any) {
+    'use strict';
+    p = { prop: p } = p;
+}