Tests: fix handling of diag.txt files in diagnostic tests with backend

Also take into account diagnostics reported via
GenerationState.collectedExtraJvmDiagnostics, and render them in the
similar format to KtDiagnostic.

Don't make the test pass if the reported list of diagnostics is empty,
because that defeats the purpose of the test.

compiler/testData/diagnostics/testsWithJvmBackend/indirectInlineCycle_ir.diag.txt

@@ -1,6 +1,3 @@
-/indirectInlineCycle_ir.kt:8:24: error: the 'inlineFun2' invocation is a part of inline cycle
-        fun method() { inlineFun2(p) }
-                       ^
-/indirectInlineCycle_ir.kt:13:5: error: the 'inlineFun1' invocation is a part of inline cycle
-    inlineFun1(p)
-    ^
+/indirectInlineCycle_ir.kt:6:24: error: The 'inlineFun2' invocation is a part of inline cycle
+
+/indirectInlineCycle_ir.kt:11:5: error: The 'inlineFun1' invocation is a part of inline cycle

compiler/testData/diagnostics/testsWithJvmBackend/inlineCycle_ir.diag.txt

@@ -1,6 +1,3 @@
-/inlineCycle_ir.kt:8:5: error: the 'inlineFun2' invocation is a part of inline cycle
-    inlineFun2(p)
-    ^
-/inlineCycle_ir.kt:13:5: error: the 'inlineFun1' invocation is a part of inline cycle
-    inlineFun1(p)
-    ^
+/inlineCycle_ir.kt:6:5: error: The 'inlineFun2' invocation is a part of inline cycle
+
+/inlineCycle_ir.kt:11:5: error: The 'inlineFun1' invocation is a part of inline cycle

compiler/testData/diagnostics/testsWithJvmBackend/suspendInlineCycle_ir.diag.txt

@@ -1,6 +1,3 @@
-/suspendInlineCycle_ir.kt:8:5: error: the 'inlineFun2' invocation is a part of inline cycle
-    inlineFun2(p)
-    ^
-/suspendInlineCycle_ir.kt:13:5: error: the 'inlineFun1' invocation is a part of inline cycle
-    inlineFun1(p)
-    ^
+/suspendInlineCycle_ir.kt:6:5: error: The 'inlineFun2' invocation is a part of inline cycle
+
+/suspendInlineCycle_ir.kt:11:5: error: The 'inlineFun1' invocation is a part of inline cycle