fix(parser): diagnose GLOBL and DATA without a symbol name

A bare GLOBL or DATA parsed without a single diagnostic while leaving a
nil Name in the tree, a pointer every downstream tool dereferences; TEXT
keeps a placeholder beside its error for exactly that reason, and GLOBL
and DATA now do the same.  The crashing input enters the corpus.

Assisted-by: GLM 5.3

format/testdata/fuzz/FuzzFormatExpansionRoundTrip/c83eeb7a26883de3

@@ -0,0 +1,2 @@
+go test fuzz v1
+string("DATA")