testsuite: fix whitespace in dg-do compile directives

Nothing seems to change here in reality at least on x86_64-pc-linux-gnu,
but important to fix nonetheless in case people copy it.

	PR rtl-optimization/48633
	PR tree-optimization/83072
	PR tree-optimization/83073
	PR tree-optimization/96542
	PR tree-optimization/96707
	PR tree-optimization/97567
	PR target/69225
	PR target/89929
	PR target/96562
	* g++.dg/pr48633.C: Fix whitespace in dg directive.
	* g++.dg/pr96707.C: Likewise.
	* g++.target/i386/mv28.C: Likewise.
	* gcc.dg/Warray-bounds-flex-arrays-1.c: Likewise.
	* gcc.dg/pr83072-2.c: Likewise.
	* gcc.dg/pr83073.c: Likewise.
	* gcc.dg/pr96542.c: Likewise.
	* gcc.dg/pr97567-2.c: Likewise.
	* gcc.target/i386/avx512fp16-11a.c: Likewise.
	* gcc.target/i386/avx512fp16-13.c: Likewise.
	* gcc.target/i386/avx512fp16-14.c: Likewise.
	* gcc.target/i386/avx512fp16-conjugation-1.c: Likewise.
	* gcc.target/i386/avx512fp16-neg-1a.c: Likewise.
	* gcc.target/i386/avx512fp16-set1-pch-1a.c: Likewise.
	* gcc.target/i386/avx512fp16vl-conjugation-1.c: Likewise.
	* gcc.target/i386/avx512fp16vl-neg-1a.c: Likewise.
	* gcc.target/i386/avx512fp16vl-set1-pch-1a.c: Likewise.
	* gcc.target/i386/avx512vlfp16-11a.c: Likewise.
	* gcc.target/i386/pr69225-1.c: Likewise.
	* gcc.target/i386/pr69225-2.c: Likewise.
	* gcc.target/i386/pr69225-3.c: Likewise.
	* gcc.target/i386/pr69225-4.c: Likewise.
	* gcc.target/i386/pr69225-5.c: Likewise.
	* gcc.target/i386/pr69225-6.c: Likewise.
	* gcc.target/i386/pr69225-7.c: Likewise.
	* gcc.target/i386/pr96562-1.c: Likewise.
	* gcc.target/riscv/rv32e_stack.c: Likewise.
	* gfortran.dg/c-interop/removed-restrictions-3.f90: Likewise.
	* gnat.dg/renaming1.adb: Likewise.