testsuite, x86, Darwin: Fix scanasm insn patterns matching asm directives.

In these cases, the scan check is too general and can match unintended
content emitted as assembler directives or EH/Debug frames, for example:

  "por"    matches 'live_support' in __eh_frame section content
  "sub"    matches '.subsections_via_symbols'
  "set"    matches '.set L$set$0...'
  "\$0,"   matches '.set L$set$0...'

The fix here is make the boundaries of the instruction explicit by
appending or prepending whitespace or characters  approprately.

gcc/testsuite/ChangeLog:

	* g++.target/i386/pr107563-a.C: Add whitespace boundary to
	scan asm match string.
	* g++.target/i386/pr107563-b.C: Likewise.
	* gcc.target/i386/pr11877-2.c: Likewise.
	* gcc.target/i386/pr11877.c: Likewise.
	* gcc.target/i386/pr92651.c: Likewise.
	* gcc.target/i386/pr98060.c: Likewise.
	* gcc.target/i386/sse2-v1ti-logic-2.c: Likewise.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>