[nomaster] SI-7519 Less brutal attribute resetting in adapt fallback

Prefers `resetLocalAttrs` over `resetAllAttrs`. The latter loses
track of which enclosing class of the given name is referenced by
a `This` node which prefixes the an applied implicit view.

The code that `resetAllAttrs` originally landed in: https://github.com/scala/scala/commit/d4c63b#L6R804

Cherry picked from 433880e91cba9e1e926e9fcbf04ecd4aeb1d73eb

Conflicts:
	src/compiler/scala/tools/nsc/typechecker/Typers.scala

2 files changed, 25 insertions, 0 deletions

diff --git a/test/files/neg/t7519.check b/test/files/neg/t7519.check
new file mode 100644
index 0000000000..164d67f595
--- /dev/null
+++ b/test/files/neg/t7519.check
@@ -0,0 +1,7 @@
+t7519.scala:5: error: could not find implicit value for parameter nada: Nothing
+    locally(0 : String) // was: "value conversion is not a member of C.this.C"
+            ^
+t7519.scala:15: error: could not find implicit value for parameter nada: Nothing
+      locally(0 : String) // was: "value conversion is not a member of U"
+              ^
+two errors found
diff --git a/test/files/neg/t7519.scala b/test/files/neg/t7519.scala
new file mode 100644
index 0000000000..aea0f35d8e
--- /dev/null
+++ b/test/files/neg/t7519.scala
@@ -0,0 +1,18 @@
+class C {
+  implicit def conversion(m: Int)(implicit nada: Nothing): String = ???
+
+  class C { // rename class to get correct error, can't find implicit: Nothing.
+    locally(0 : String) // was: "value conversion is not a member of C.this.C"
+  }
+}
+
+object Test2 {
+  trait T; trait U
+  new T {
+    implicit def conversion(m: Int)(implicit nada: Nothing): String = ???
+
+    new U { // nested anonymous classes also share a name.
+      locally(0 : String) // was: "value conversion is not a member of U"
+    }
+  }
+}